Code I used to create twitter follow buttons from profile links

converttwits.js

//Add the twitter-follow-button class to all anchors that contain twitter
//The selector could be tweaked to be more specific.
$("a[href*=twitter]").addClass("twitter-follow-button");

//Add the twitter API code dynamically
! function (d, s, id) {
    var js, fjs = d.getElementsByTagName(s)[0];
    if (!d.getElementById(id)) {
        js = d.createElement(s);
        js.id = id;
        js.src = "//platform.twitter.com/widgets.js";
        fjs.parentNode.insertBefore(js, fjs);
    }
}(document, "script", "twitter-wjs");