Basics for a bookmarklet

gistfile1.txt

javascript: (function () {
    _bookmarklet = document.createElement('script');
    _bookmarklet.id = 'bookmarklet';
    if (document.getElementById(_bookmarklet.id)) {
        yimmelet.init();
    } else {
        _bookmarklet.type = 'text/javascript';
        _bookmarklet.src = 'http://assets.domain.com/jsfile.js?x=' + (Math.random());
        document.getElementsByTagName('head')[0].appendChild(_bookmarklet);
    }
})();