Parse query_string and fill form

pqsaff.js

function pqsaff () {
	this.vars = (window.location.search.length > 1) ?
		window.location.search.substring(1).split("&") :
		[];
}
pqsaff.prototype = {
	param: function (s) {
		var p = s.split("=");

		this.name = p.shift();
		this.value = unescape(p.join("="));
	},
	fill: function (name,xlate) {
		var f = document.forms[name];

		if (f && this.vars.length) {
			for (var i = 0; i < this.vars.length; i++) {
				var v = new this.param( this.vars[i] );
				var field = f.elements[xlate ? xlate[v.name] : v.name];

				if (field) {
					field.value = v.value;
				}
			}
		}
		return f;
	}
};
/*
 * Usage:
 * 
 *	(new pqsaff()).fill("theFormName");
 * 	(new pqsaff()).fill("theFormName",{email:"mail",firstName:"fn",lastName:"ln"});
 *
 */