javascript: parsing variables in the URL

so, my URL is example.com/?ref=person

but ref is null after the regex. What am I doing wrong here?

function getReferer(){
    var regex = new RegExp(/ref=(.+)/);
    var ref = regex开发者_运维百科.exec(window.location.ref);
    alert(ref);
    if (ref == null) return "";
    else return ref[1];
}

Replace window.location.ref by window.location.href. Don't use new RegExp if not necessary, it's slower.

function getReferer(){
    var regex = /ref=(.+)/;
    var ref = regex.exec(window.location.href);
    alert(ref);
    if (ref == null) return "";
    else return ref[1];
}