鼠标点击变灰

<script>
 function doClick_new(divPage)
{
  document.getElementById("idBox").style.display="block";
  document.all.ly.style.width=document.body.clientWidth;  
  document.all.ly.style.height=document.body.clientHeight;  
  document.all.ly.style.display='block';  
}
function doClick_close()
{
  document.getElementById("idBox").style.display="none";
  document.all.ly.style.display='none'; 
}
      </script>

 

<a  onClick="doClick_new()" style="color:Black;cursor:pointer" >郑重承诺</a> </span> </p>
           
<div id="idBox" style="position:absolute; display:none; z-index:999;width:586px; height:402px; background:#000; margin-top:-520px; margin-left:330px;">
      <div id="tc">
      <div id="tc_r1"><span id="msgShut" style="cursor:pointer" onclick="doClick_close()" >关闭</span></div>
<div id="tc_r2"></div>
<div id="tc_r3"></div>
<div id="tc_r4"></div>
<div id="tc_r5"></div>
<div id="tc_r6"></div>
<div id="tc_r7"></div>
<div id="tc_r8"></div>
      </div>                 
</div>

<div id="ly" style="position: absolute; top: 0px; filter: alpha(opacity=50); background-color: #777;
        z-index: 2; left: 0px; display: none;">
</div>