Javscript 获取 URL 参数

<script type="text/javascript"> 
<!-- 
function getvalue(name)
{
 var str=window.location.search;
 if (str.indexOf(name)!=-1)
 {
  var pos_start=str.indexOf(name)+name.length+1;
  var pos_end=str.indexOf("&",pos_start);
  if (pos_end==-1)
  {
   return str.substring(pos_start);
  }
  else
  {
   return str.substring(pos_start,pos_end)
  }
 }
 else
 {
  return "";
 }
}
//for test: http://localhost/a.html?p1=11&p2=22
document.write(location.search); 
alert(getvalue("p1"));
alert(getvalue("p2"));
//--> 
</script>