Returns the value for a certain URL parameter. If your URL is http://example.com/index.html?year=2013 the function getUrlParam(year) will return the string "2013".

getUrlParam.js

function getUrlParam(name) {
    name = name.replace(/[\[]/, "\\\[").replace(/[\]]/, "\\\]");

    var regexS = "[\\?&]" + name + "=([^&#]*)";
    var regex = new RegExp(regexS);
    var results = regex.exec(window.location.href);

    if (results == null) {
        return "";
    } else {
        return results[1];
    }
}