jquery ajax with blockUi

Question

hi, i am using jquery ajax with blockUI, as shown below.

$(document).ready(function(){

    $("div[id^=DAY_ID_]").click(function () { 
      var dayId = $(this).text();  
      alert("Selected Day:::"+dayId);     
      $().ajaxStart(function(){
           $.blockUI({ message: '<h5><img src="image/spinner.gif" /> Loading...</h5>' });
          });

        $().ajaxStop($.unblockUI);

        $.ajax({
                url : "XXXXX.do?button=xxxxxx&dayId="+dayId,
                cache: false,
                success : function (data) {
                    $("#xxxxxxDivId").html(data);

                }
        });
    });
});

My problem is loading mask is perfectly coming while ajax start, but it loading mask is not clearing after stop function.i inserted .unblockUI in the succes method also.it is not clearing .code is perfectly working in the firefox but it is not working in ie.Any idea please

usman sk