function queryStringValue(findName) {
    var name = new String();
    var value = new String();
    var querystring = document.location.href;
    if (querystring.indexOf('?') == -1) {
        return 'null';
    }
    querystring = querystring.split('?');
    querystring = querystring[1].split('&');
    for (q = 0; q < querystring.length; q++) {
        var pair = querystring[q].split('=');
        name = pair[0].toLowerCase();
        value = pair[1].toLowerCase();
        if (findName.toLowerCase() == name) {
            return value;
        }
    }
} 

function Querystring(qs) { // optionally pass a querystring to parse
    this.params = {};

    if (qs == null) qs = location.search.substring(1, location.search.length);
    if (qs.length == 0) return;

    // Turn <plus> back to <space>
    // See: http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13.4.1
    qs = qs.replace(/\+/g, ' ');
    var args = qs.split('&'); // parse out name/value pairs separated via &

    // split out each name=value pair
    for (var i = 0; i < args.length; i++) {
        var pair = args[i].split('=');
        var name = decodeURIComponent(pair[0]);

        var value = (pair.length == 2)
			? decodeURIComponent(pair[1])
			: name;

        this.params[name] = value;
    }
}

Querystring.prototype.get = function(key, default_) {
    var value = this.params[key];
    return (value != null) ? value : default_;
}

Querystring.prototype.contains = function(key) {
    var value = this.params[key];
    return (value != null);
}