Javascript Array insertAfter(elem, after)

Array.prototype.insertAfter = function(elem, after) {
    var tmp_array = [];
    while (this.length) {
        var next = this.pop();
        if (next !== after) {
            tmp_array.push(next);/*from ww  w.  ja  va2  s .  c  o  m*/
        } else {
            this.push(next);
            break;
        }
    }
    this.push(elem);
    while (tmp_array.length) {
        this.push(tmp_array.pop());
    }
};