Petition brought under article 78 CPLR in the nature of a writ of prohibition, unanimously dismissed, without costs. Prohibition does not lie to correct alleged error or to prevent prospective error where the court has jurisdiction of the subject matter before it. The extraordinary remedy sought may not be employed where such error, if any, “ may be remedied by way of appeal, and where no extreme necessity is shown.” (Matter of Hodes v. Helman, 19 A D 2d 603, 604.) There is, therefore, no basis upon which to grant petitioner the relief he seeks. Concur — Breitel, J. P., Rabin, Yalente, Stevens and Steuer, JJ.