js 获得url参数

<script type="text/javascript">
var c="http://ww.www.com/item.htm?id=23423";
var d=parse_url(c);
alert(d['id']);
function parse_url(url){ //定义函数
 var pattern = /(\w+)=(\w+)/ig;//定义正则表达式
 var parames = {};//定义数组
 url.replace(pattern, function(a, b, c){
  parames[b] = c;
 });
 return parames;
}


</script>