delivered the opinion of the Court.
This is an appeal and cross-appeal from a summary judgment in a claim and delivery action. The District Court of Yellowstone County awarded each party one-half of the monies in a savings account and two certificates of deposit in a savings and loan association. We reverse.
The uncontradicted facts disclose that Marie Sanders, who lived on a farm near Ballatine, Montana, opened a savings account and two certificates of deposit in 1972 and 1974 at Security Federal Savings and Loan in Billings, Montana. On October 28,1975, the name of her son, Leo B. Baker, who was buying the farm from Sanders, was added as a joint tenant to the three accounts which, by July 30, 1978, (through various deposits and interest accumulation) had come to total $26,182.35.
The signature cards for the three accounts, signed by Baker and Sanders contained the following language:
“. . . It is agreed by the signatory parties with each other and by the parties with the Association that any funds placed in or added to the account by any one of the parties is and shall be conclusively intended to be a gift and delivery at that time of such funds to the signatory party or parties to the extent of *497his or their pro rata interests in the account.” The facts indicate that Mrs. Sanders did not intend to gift any portion of the savings accounts to Baker and that his name was placed on the account so he could withdraw money for her expenses, if needed. Also, a bank officer’s affidavit indicated that in 1978, three years after Baker’s name had been placed on the accounts, Baker told the officer that the funds in the accounts belonged to his mother and were not his money.
In 1975, Mrs. Sanders gave the passbook and certificates to Baker. In May, 1978, Mrs. Sanders was hospitalized for about a week in Billings, Montana, at which time her granddaughter, Patsy Jean Anderson, came from Arizona to visit her. In early June, after Mrs. Sanders had been released from the hospital she went to Arizona to see her granddaughter.
On June 29,1978, Mrs. Sanders executed her will, giving the bulk of her estate to Anderson (except for a few cash bequests) and named Anderson as her personal representative. On July 7, Sanders, through her attorney in Billings, made a written demand on Baker for the return of the passbook and certificates so she could withdraw the money. Baker refused and on August 3,1978, Sanders filed the instant suit for their return.
Thus Marie Sanders commenced this action on August 3, 1978, alleging that her son, Leo Baker, was wrongfully retaining the two certificates of deposit and passbook. She asked for their return and that Baker’s name be removed therefrom. In the alternative, she asked for the total sum of $26,182.35 in damages, if the certificates of deposit and passbook were not returned.
Baker filed an answer on October 20, asserting that he had the right to retain the certificates of deposit and passbook and further alleging that Sanders was incompetent and acting under coercion and undue influence. On November 18, 1978, Mrs. Sanders died in Arizona and on November 30, Baker withdrew all the money from the three accounts.
After Sanders’ death the personal representative, Patsy Jean Anderson, was substituted as plaintiff. On March 5,1979, the defendant filed an amended answer, raising the additional defenses of statute of limitations, laches and equitable estop*498pel. After a substitution of counsel for defendant, both sides moved for summary judgment, éach seeking the total amount on deposit.
On July 10,1980, the District Court entered judgment granting each of the parties one-half of the total funds on deposit. Baker now appeals, contending he is entitled to all of the accounts as the surviving joint tenant. Anderson cross-appeals, claiming that she, as residuary legatee of Sanders, is entitled to the full balance.
The issues on appeal can be stated as follows:
1. Is parol evidence admissible to show the funds were not intended as a gift by Sanders to Baker?
2. Is Sanders’ suit barred by the applicable statute of limitations, laches, or equitable estoppel?
3. Is the plaintiff entitled to interest calculated from the date Baker withdrew all funds from the three bank accounts?
We reverse the trial court and find that the plaintiff personal representative should have been granted summary judgment in her claim and delivery action.
With regard to the first issue, Baker argues that State Board of Equalization v. Cole (1968), 122 Mont. 9, 195 P.2d 989, and Casagranda v. Donahue (1978), 178 Mont. 479, 585 P.2d 1286, are controlling. In Cole, the decedent created five joint bank accounts between herself and various relatives, all within three years of her death. After the decedent’s death, the trial court imposed an inheritance tax measured by one-half of the value of the accounts. The questions presented on appeal included whether the state was entitled to an inheritance tax on the full amount of the joint bank accounts, or just one-half of the accounts. The court, in finding that the half-interest in the bank account which the joint tenants received was taxable as a transfer in contemplation of death, made the following statements:
“Of course if the transfer by the donor to the joint account be regarded as a gift it has to satisfy all the requirements of a valid gift inter vivos. The essential requisites of a gift inter vivos are delivery, accompanying intent, and acceptance by the donee. [Citing cases.]
*499“The first question is the intention of the parties making the deposit (5 Michie, Banks & Banking, p. 101, § 46.) Such intention was discussed in Hill v. Badeljy, 107 Cal.App. 598, 605, 290 P. 637, 640, where the court declared, ‘The question involved in cases of this character is the intention of the parties making the deposit, and where such intention is evidenced by a written agreement, as was done in the case at bar, this question of intention ceases to be an issue, and the courts are bound by the written agreement.’ The above quotation was cited and approved by this court in Ludwig v. Montana Bank & Trust Co., 109 Mont. 477, 502, 98 P.2d 377, 379.
“The Montana court also said, quoting from 9 C.J.S., Banks & Banking, § 286, ‘Where no other evidence of intent is available, the form of the deposit may control; but when such intent is evidenced by a written agreement, the question of intention ceases to be an issue and the courts are bound by the agreement.’ Ludwig v. Montana Bank & Trust Co., supra, at page 502 of 109 Mont., at page 389 of 98 P.2d.
“In this jurisdiction the signing of the signature card containing an agreement that the deposit was payable to either of the co-depositors or the survivor settled the question of the donative intent of the donor to make a gift in joint tenancy. See In re Sullivan’s Estate, 112 Mont. 519, 118 P.2d 383.” 122 Mont. at 14-15, 195 P.2d at 992.
In Casagranda, supra, the decedent placed funds in two savings accounts, naming himself and the defendant as joint tenants with the right of survivorship. After his death, the executrix brought suit to quiet title in the accounts and the court awarded the money to the defendant, as the surviving joint tenant.
The court elaborated on the Cole holding with the following language:
“Cole stood for the proposition that, in Montana, signing a signature card containing an agreement that the deposit is payable to either of the co-depositors or the survivor settles the question of donative intent to make a joint tenancy. Appellant cites an Arizona decision, O’Hair v. O’Hair (1973), 109 Ariz. 236, 508 P.2d 66, wherein it was held that the mere form of a bank account is not regarded as sufficient to establish the *500intent of the depositor to give another a joint interest in or ownership of it. We find the Montana rule represents a more reliable manner for determining questions concerning the ownership of joint bank accounts. This should not be mistakenly understood to mean we have no concern for the depositor’s intentions. Intention is clearly expressed on the face of the signature card. Additional evidence is unnecessary . . .” 178 Mont. at 483-484, 585 P.2d at 1288.
However, we distinguish the instant case from Cole and Casagranda for the following reasons. In neither Cole no r Casagranda was there any attempt made during the lifetime of the donor-depositor, as there was here, to divest the other joint tenant of his or her interest in the account. In spite of the conclusory gift language contained on the signature card signed by Baker and Sanders, the uncontroverted evidence here shows that no gift was intended, i.e., Baker was named as a joint tenant for convenience purposes only. The legal effect of Sanders’ claim and delivery action, filed during her lifetime, was to establish judicially her exclusive ownership to the funds in the account cutting off Baker’s right of survivorship and to allow Baker to take, solely on the basis of the language contained on the signature card, would result in a substantial miscarriage of justice.
We therefore hold that where, as here, a depositor during his or her lifetime raises the issue of ownership of funds in a joint tenancy account, the statements on the signature card are not conclusive and additional evidence may be examined to ascertain the true intent of the parties. We are especially cognizant of the fact that many elderly people, whose means of transportation is limited or whose physical condition is deteriorating, execute the signature card in conjunction with a younger relative so the younger person may make withdrawals at the other’s direction.
We are also mindful that the signature cards are forms containing language drafted by the depository institution. While the language thereon may very well describe the agreements between the depositor and the depository, it can hardly be expected to accurately express the intentions and relationships between the joint tenants about which the *501depository typically has little, if any, knowledge. Where the donor-depositor, as in the instant suit, indicates during her lifetime that her intent is other than that revealed on the signature card, we hold such evidence admissible.
Other courts have stated this same thought in a similar manner. For example, in Harrington v. Emmerman (D.C. Cir. 1950), 186 F.2d 757, which involved two female joint tenants, it was said:
“To be sure, the deposit agreement described the two women as ‘joint owners’ and provided that either might draw on the account; but the agreement was on a printed form supplied by the building association, presumably for its own purpose and protection. Some such form probably would have been required by it to safeguard its own interests even had Miss Emmerman then stated the arrangement was merely for the convenience of Mrs. Carlin. The writing was conclusive as between the two women on the one hand and the building association on the other, but was not conclusive between the individuals as to whether a present gift had been intended.” 186 F.2d at 761. The Washington Supreme Court stated it thus:
“. . . [T]he signature card is invariably in a form provided by the depository institution which has undoubtedly drafted it to protect the institution rather than express the terms of an agreement between the depositors.” In re Guardianship of Matt (1969), 75 Wash.2d 123, 132, 449 P.2d 413, 418.
When a depositor opens a savings account at an institution he must accept the forms drafted by the depository and proferred him to sign or go elsewhere. We have held in other “take-it-or- leave-it” situations, where adhesion contracts are involved, that the terms are to be construed against the drafter and any ambiguities are to be resolved in favor of the party having no voice in arriving at the document’s terms, Fitzgerald v. Aetna Ins. Co. (1978), 176 Mont. 186, 577 P.2d 370. We feel this reasoning also supports our conclusion that the language of the signature cards signed by Baker and Sanders should not be the “only word” on what their actual relationship was intended by them to be.
*502Further, the parol evidence rule in Montana is not an obstacle for the introduction of evidence other than simply the signature card language. Section 28-2-905, MCA, provides in pertinent part:
“When extrinsic evidence concerning a written agreement may be considered. (1) Whenever the terms of an agreement have been reduced to writing by the parties, it is to be considered as containing all those terms. Therefore, there can be between the parties and their representatives or successors in interest no evidence of the terms of the agreement other than the contents of the writing except in the following cases:
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“(2) This section does not exclude other evidence of the circumstances under which the agreement was made or to which it relates, as described in l-U-102, or other evidence to explain an extrinsic ambiguity or to establish illegality or fraud.” (Emphasis added.) Section 1-4-102, MCA, in turn provides:
“Consideration of circumstances surrounding execution. For the proper construction of an instrument, the circumstances under which it was made, including the situation of the subject of the instrument and of the parties to it, may also be shown so that the judge be placed in the position of those whose language he is to interpret.” The circumstances under which the signature cards were executed here shows that no gift was intended by Sanders to Baker when the cards were signed.
In a similar situation involving unambiguous lien waivers, parol evidence was held admissible to show the circumstances of the parties and their real purpose in executing and receiving the lien waivers. Fillbach v. Inland Construction Corp. (1978), 178 Mont. 374, 584 P.2d 1274. There a subcontractor signed a series of lien waiver forms in which he acknowledged receipt of specified sums of money in full.payment for labor and materials furnished by him to a specified date and waived all rights to file mechanics liens against the premises. Nonetheless we held parol evidence admissible to show that the lien waivers were executed to enable the subcontractor to receive money from the owner from time to time and were not *503intended to constitute payment in full to the specified date as stated in the release.
Likewise in Kussler v. Burlington Northern Inc. (1980), Mont., 606 P.2d 520, 37 St.Rep. 240, we adopted prospectively the rule from Restatement of Torts, Second, § 885, and held that in the future unless a general release form specifically states otherwise, parol evidence is admissible to show whether the parties intended to release other parties or whether the release was actually intended to constitute full compensation in the face of unambiguous language to that effect in the release form.
Other jurisdictions have similarly endorsed the use of parol evidence in joint bank account situations. In Matt, supra, the court found that the execution of the signature card raised a rebuttable presumption of joint tenancy and it would make little sense to refuse parol evidence to rebut the presumption. In Murray v. Gadsden (D.C. Cir. 1952), 197 F.2d 194, 33 ALR2d 554, the court examined the parol evidence rule exception, which allows an inquiry into the object of the parties in executing the instrument, and admitted the parol evidence. See Annot., Parol Evidence Rule as Applied to Deposit of Funds in Name of Depositor and Another (1954), 33 ALR2d 569.
The case of Harrington, supra, is similar to the case at bar. In Harrington, the donor-depositor continued to treat the joint account as her own during her lifetime and, subsequent to the creation of the account, her representative filed suit because the other joint tenant would not surrender the passbook. After an answer had been filed but before any further action was taken, the depositor died.
The Harrington court found that the filing of the suit by the donor-depositor cut off any survivorship rights of the other joint tenant and whatever interest the depositor had passed to her executor. The case was then remanded for the survivor to try to prove that the decedent intended a gift of at least part of the account to the survivor. In the case at bar, however, there is uncontradicted evidence apart from the signature card that Sanders never intended a gift of any part of the accounts to Baker, that Baker was named as a joint tenant for convenience purposes only, and that Baker understood this. *504See also Brennan v. Timmins (1963), 104 N.H. 384, 187 A.2d 793 and Brennen v. Timmins (1964), 105 N.H. 464, 202 A.2d 229.
In two cases wherein courts have construed language almost identical to that at issue here, additional evidence was allowed. In Graves v. Graves (1963), 42 Ill.App.2d 438, 192 N.E.2d 616, the court examined evidence other than merely the words in the agreement, finding that the record, in addition to the agreements, showed that a gift was intended. In Estate of Macak (1973), 14 Ill.App.3d 261, 302 N.E.2d 436, the court similarly looked at the evidence on the record, finding no evidence to rebut the presumption in favor of the surviving joint tenant. It should be noted that in both Graves and Macak there was evidenc e that the donor-depositor intended a gift to the other joint tenant. In this case at bar, however, the evidence is exactly to the contrary. See Annot., Creation of Joint Savings Account or Savings Certificate as Gift to Survivor (1972), 43 ALR3d 971, 1018.
With regard to the second issue, Sanders’ action is not barred by the two-year statute of limitations, section 27-2-207, MCA. This statute does not begin to run until after there has been a demand and refusal of delivery. Interstate Manufacturing Co. v. Interstate Products Co. (1965), 146 Mont. 449, 408 P.2d 478. Here, the statute began to run at the time Sanders made written demand on Baker for the return of the passbook and certificates, i.e., July 7, 1978, and Sanders filed her suit less than one month later, well within the required time.
The doctrine of laches has no application to the present case.
Laches requires negligence in the assertion of a claim and exists when there has been an unexplained delay of such duration as to render the enforcement of the right inequitable. Brabender v. Kit Manufacturing Co. (1977), 174 Mont. 63, 67-68, 568 P.2d 547, 549. There is no evidence here that Mrs. Sanders was negligent in prosecuting her claim. As stated above, she waited less than a month after her written demand was refused before filing suit.
*505 Similarly, equitable estoppel does not apply here. This principle requires that the party claiming it relied on a representation or promise to his detriment, Carroccia v. Todd (1980), Mont., 615 P.2d 225, 37 St.Rep. 1437. Baker has not shown any reliance to his prejudice, and thus cannot have a legitimate defense based on equitable estoppel.
With regard to the third issue, the trial court correctly calculated interest from the date that the three accounts were closed by Leo Baker and the proceeds converted to his own use, which was November 30, 1978. The applicable statute is section 27-1-320, MCA, which provides in pertinent part:
“Conversion of personal property. (1) The detriment caused by the wrongful conversion of personal property is presumed to be:
“(a) the value of the property at the time of its conversion with the interest from that time. . .” Accord, Galbreath v. Armstrong (1948), 121 Mont. 387, 193 P.2d 630.
Reversed and remanded to the District Court for entry of judgment for plaintiff and cross-appellant Anderson for the sum of $26,182.35, interest thereon at the statutory rate from November 30, 1978 to date of judgment, and costs.
MR. JUSTICES HARRISON, SHEA, DALY and WEBER concur.