getQueryString

String.prototype.getQueryString = function(name)
{
var reg = new RegExp("(^|&|\\?)"+ name +"=([^&]*)(&|$)"), r;
if (r=this.match(reg)) return unescape(r[2]); return null;
};
var s="http://localhost/index.htm?a=10&b=20"; //window.location.href;
alert(s.getQueryString("a"));
alert(s.getQueryString("b"));