back pattern revisited

back.js

// check: if we came frome our own site, just use history.back()
// as simple as it gets.
on_back_click: function(e) {
    // this check could be further enhanced, but works quite well already.
    if (document.referrer.indexOf(window.location.host) !== -1) {
        e.preventDefault();
        history.back();
    }
}