ASP.Net MVC Ajax form with jQuery validation

Try adding an OnBegin callback to the AjaxOptions and return the value of $(‘form’).validate().form() from the callback. Looking at the source it appears that this should work.

function ajaxValidate() {
   return $('form').validate().form();
}

<% using (Ajax.BeginForm("Post", new AjaxOptions
       {
           UpdateTargetId = "GBPostList",
           InsertionMode = InsertionMode.InsertBefore,
           OnBegin = "ajaxValidate",
           OnSuccess = "getGbPostSuccess",
           OnFailure = "showFaliure"
       }))
       { %>

EDIT updated with correct callback name.