Event.add(window, 'load', function() {

  Event.add('add-element', 'click', function() {

    // get ID from dialog
    var id = 20;

    // check if this ID is in the selected array, if yes, return
    for (var i = 0; i < choice.length; i++) {
        if (id == choice[i]) {
            return;
        }
    }

    // append ID to array
    choice.push(id);

    // add row with info to screen (and place ID in the removebutton element)
    addrow('Heinz Ketchup',allitems[id],id, 'multirows', choice);

  });
});

var Event = {
  add: function() {
    if (window.addEventListener) {
      return function(el, type, fn) {
        Dom.get(el).addEventListener(type, fn, false);
      };
    } else if (window.attachEvent) {
      return function(el, type, fn) {
        var f = function() {
          fn.call(Dom.get(el), window.event);
        };
        Dom.get(el).attachEvent('on' + type, f);
      };
    }
  }()
};