select box (combo) is not responding

Question

Hello I am using following javacript code

$("a.adminlink").click(function(){
   $("#bigpopup").fadeIn();
   //$("a.activetablink").removeClass("activetablink");
   //$("a.tablink[href=" + $(this).attr("href") + "]").addClass("activetablink");
   $.get($(this).attr("href"),{},function(response){
      $("#tabmenu").html(response.menu);
      $("#formblockcontent").html(response.content);
      $("#notinvisible").fadeIn();
      bindtoolpicker();
      if(toppanelshown) {
        toppanel();
      }
   },"json");
   return false;
});

and php script return a json response with two key value one is menu and another is content So problem is that when combo box is no responding when I click on it . This error occurs only in chrome and Safari for FF and IE it work fine

Please help me

Thanks in advance