FireFox beforeunload problems

$(window).bind("beforeunload",function(){开发者_JS百科
    return "cant be seen in ff";
});

The problem is that i can't see the "cant be seen in ff" on the confirm box in my FireFox browser, but works well in other browsers(IE Chrome)

Any solutions??

See this: https://bugzilla.mozilla.org/show_bug.cgi?id=588292

It looks like forefox decided to remove the support for the beforeunload as we know it.

confirmOnPageExit : function( display ) {
      if ( true == display ) {
        var message;
        /* if unsaved changes exist, display a warning */
        if (false !== form_structure.unsaved_changes) {
            message = 'Warning!  Changes to the form builder have not been saved.';
                     return message;
        }
      }
},

window.onbeforeunload = confirmOnPageExit( false );

do this

<script>
    window.onbeforeunload = function(){
         return "cant be seen in ff";
    }
</script>