Ajax+Jquery withe IE causing problems

Ajax+Jquery withe IE causing problems

Hello, my code works fine with fire fox but for some reason it fails to work on IE. I think it's mouseup event that crashes it. The events just stops happening but mouseclick events still work. Here is the code where the event is defined:
$("#report").mouseup(function(){
      var str = $("#report").val();
      if(str == "concreport")   {
         $(".building").hide();
         $(".info").empty();
         $("#submit").attr("action", "PDFconclusion.php");
         }
      else if(str == "mappingreport")   {
         $(".building").show();
         $("#submit").attr("action", "PDFmapping.php");
      }
   });


Why does it work on fire fox and not on IE? Thanks in advance to everyone replying.