Query string access in javascript

qs.js

function setGetParam() {
	var url = arguments[2] || location.href;
	if (arguments[0] instanceof Object) { // hash object
		for(var arg in arguments[0]) {
			if (!arg || !arguments[0][arg]) continue;
			url = setGetParam(arg, arguments[0][arg], url);
		}
	} else if (typeof arguments[0] === 'string' && arguments[1]) {
		paramName = arguments[0];
		paramValue = arguments[1];
		if (url.indexOf(paramName + '=') >= 0) {
			var prefix = url.substring(0, url.indexOf(paramName));
			var suffix = url.substring(url.indexOf(paramName)).substring(url.indexOf('=') + 1);
			suffix = (suffix.indexOf('&') >= 0) ? suffix.substring(suffix.indexOf('&')) : '';
			url = prefix + paramName + '=' + paramValue + suffix;
		} else {
			if (url.indexOf('?') < 0)
				url += '?' + paramName + '=' + paramValue;
			else
				url += '&' + paramName + '=' + paramValue;
		}

		if (arguments[2]) return url;
	}

	if (url != location.href) {
		location.href = url;
	}
}

function getParam(name) {
    return decodeURI(
        (RegExp(name + '=' + '(.+?)(&|$)').exec(location.search)||[,null])[1]
    );
}