Retrieve URL Parameters <http://stackoverflow.com/a/1099670>

getQueryParams.js

/**
 * Retrieve URL Parameters <http://stackoverflow.com/a/1099670>
 * @param {string} [qs=window.location.search] - Query string
 * @returns {object}
 *
 * @example
 *  var query = getQueryParams(document.location.search);
 *  alert(query.foo);
 */
function getQueryParams(qs) {
    qs = qs || window.location.search;
    
    qs = qs.split('+').join(' ');

    var params = {},
        tokens,
        re = /[?&]?([^=]+)=([^&]*)/g;

    while (tokens = re.exec(qs)) {
        params[decodeURIComponent(tokens[1])] = decodeURIComponent(tokens[2]);
    }

    return params;
}