Get Url params

urlParams.js

function getQueryParams(qs) {
    qs = qs.split("+").join(" ");

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

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

    return params;
}

var query = getQueryParams(document.location.search);
alert(query.foo);