JS判断页面SUBMIT是否执行完

<script language="javascript" type="text/javascript">
    //<![CDATA[
    $(document).ready(function() {
        $('form').bind("submit", function(obj) {
        //当页面没有validator控件是默认验证通过 
        if (sth) { //下载Excel不要显示状态
                if (typeof (Page_IsValid) == 'undefined' || Page_IsValid) {
                    if (LoadingFlag) {
                  
                        $('#loading').modal({ overlayId: 'loadingbg', containerId: 'loading-container',//css
 close: false, onOpen: Loading.open });
                     
                    } else {
                        LoadingFlag = true;
                    }
                }
            }
        });
    });
    //]]>
</script>