关于遮罩

<div id="coverDiv" style="top: 0px; left: 0px;position: absolute; z-index: 1999;  width: 100%; height: 100%; border: solid 0px #3E9FEC; background: #fff;filter:alpha(opacity=40);"></div>
  <div class="container" style="position: absolute; z-index: 2000;"></div>


/** 打开DIV */
   function openDiv(taskId)
   {
    obj$("coverDiv").style.zIndex="2001";
       obj$("auditTaskDiv").style.zIndex="2002";
       obj$("auditTaskDiv").style.display="block";
       obj$("auditTaskId").value=taskId;
   }
   
   /** 关闭DIV */
   function closeDiv()
   {
    obj$("coverDiv").style.zIndex="1999";
       obj$("auditTaskDiv").style.zIndex="1998";
       obj$("auditTaskDiv").style.display="none";
   }