IE中的ajax不显示JQuery对话框

$('#package').sSelect().change(function(){


                $.ajax({
                    url: 'scripts/change_script.php',
                    type: 'POST',
                    dataType: 'json',
                    data:{account_id:2},
                    beforeSend: function() {
                        $( "#wait_dialog" ).dialog( "open" );
                    },
                    success: function(data) {
                        if(data.success)
                        {
                            location.reload();
                        }
                        else
                        {

                        }
                    }
                });

                return false;
            });

this code work with Firefox, chrome but dialog is not displayed for IE. can anybody help me?

hi if you are using jquery 1.4.2 this SO question jQuery ajaxSetup beforeSend not executing in IE8 might be of interest to you.