GetUrlParam:function GetUrlParam(param){
var reg = new RegExp("(^|&)"+ param +"=([^&]*)(&|$)");
var r = window.location.search.substr(1).match(reg);
if(r!=null)return unescape(r[2]); return null;
},
param:传入参数名字
例：
var docId = "101";
var randnum = Math.random();
url="../page/jtformat?docId="+docId+"&randnum="+randnum;
this.GetUrlParam（docId）返回101；
this.GetUrlParam（randnum）返回随机数randnum；