Get query string values in JavaScript

gistfile1.js

// Revised, cooler.
function getParameterByName(name) {
 
    var match = RegExp('[?&]' + name + '=([^&]*)')
                    .exec(window.location.search);
 
    return match ?
        decodeURIComponent(match[1].replace(/\+/g, ' '))
        : null;
 
}