自动关闭窗口的JavaScript

<script language="javascript">
setTimeout("Close()",1000);
function Close()
{
 var ua=navigator.userAgent
 var ie=navigator.appName=="Microsoft Internet Explorer"?true:false
 if(ie)
 {
      var IEversion=parseFloat(ua.substring(ua.indexOf("MSIE ")+5,ua.indexOf(";",ua.indexOf("MSIE "))))
  if(IEversion< 5.5)
  {
   var str  = '<object id=noTipClose classid="clsid:ADB880A6-D8FF-11CF-9377-00AA003B7A11">'
       str += '<param name="Command" value="Close"></object>';
       document.body.insertAdjacentHTML("beforeEnd", str);
       document.all.noTipClose.Click();
  }
      else
  {
       window.opener =null;
       window.close();
      }
   }
 else
 {
  window.close()
   }
}
</script>