js 获取url参数的方法

function getParam(url,key){

				if(url.indexOf('?')<0)return null;
				url = url.split('?')[1];
				url = url.split('&');

				var i = 0 , len = url.length, sub, obj = {};

				for( ; i < len; i++){
					sub = url[i].split('=');
					obj[sub[0]] = sub[1];
				}

				return obj[key];
			}

window.onload=function() {
			
				//获取url
				var url=window.location.href;
				 
				var arg=getParam(url,"id")+" "+getParam(url,"pl")+" "+getParam(url,"kw");
				
//操作frame				
window.frames["buy"].document.getElementById("ordercode").value = arg;
			}