弹出层并屏蔽父窗口(防刷新、后退、关闭窗口)

 <script type="text/javascript" language="javascript">

   document.οnmοuseοver=function(){

     if(event.srcElement.id != "tijiao"){

  window.onbeforeunload = function(){

      return "如果您离开本页面，那么您本次的操作将视为无效！";

  }

     }

     else{

  window.onbeforeunload = null;

     }

 };

 function ShowNo()                        //隐藏两个层

        {

            document.getElementById("doing").style.display="none";

            document.getElementById("loading").style.display="none";

        }

        function $(id)        

        {

            return (document.getElementById) ? document.getElementById(id) : document.all[id] ;

        }

        function showFloat()                    //根据屏幕的大小显示两个层

        {

            var range = getRange();

            $('doing').style.width = range.width + "px";

            $('doing').style.height = range.height + "px";

            $('doing').style.display = "block";

            document.getElementById("loading").style.display="";

        }

        function getRange()                      //得到屏幕的大小

        {

              var top     = document.body.scrollTop;

              var left    = document.body.scrollLeft;

              var height  = document.body.clientHeight;

              var width   = document.body.clientWidth;

              if (top==0 && left==0 && height==0 && width==0)

              {

                top     = document.documentElement.scrollTop;

                left    = document.documentElement.scrollLeft;

                height  = document.documentElement.clientHeight;

                width   = document.documentElement.clientWidth;

              }

              return  {top:top  ,left:left ,height:height ,width:width } ;

        }

    </script>

    <style type="text/css"> 

            body{margin:0px;}

    </style>

<form id="form1" runat="server">

    <a id="tijiao" href="javascript:void(0)" target="_blank" rel="external nofollow" οnclick="showFloat()">提交</a>

    <div style="margin:auto;height:500px; width:300px;text-align:center;line-height:500px;">此处添加表单信息</div>   

    <!--加一个半透明层-->

    <div id="doing"  style="filter:alpha(opacity=30);-moz-opacity:0.3;opacity:0.3;background-color:#000;width:100%;height:100%;z-index:1000;position: absolute;left:0;top:0;display:none;overflow: hidden;">

    </div>   

    <!--加一个等待层-->

    <div id="loading" style="border:solid 10px #898989;background:#fff;padding:10px;width:780px;z-index:1001; position: absolute; display:none;top:50%; left:50%;margin:-200px 0 0 -400px;">

            <div style="padding:3px 15px 3px 15px;text-align:left;vertical-align:middle;" >

                <div>

                    数据正在请求中，请稍等...

                </div>

            </div>

      </div>

    </form>