file.js

// Still incorrect, but less incorrect.
var itemOne : GameObject;
var itemTwo : GameObject;
var objects : new Array();

objects.Push(itemOne);
objects.Push(itemTwo);

// Make one of each object.
for(var i : int; i < objects.length; i++) {
  var object = objects[i];
  Instantiate(object, /* ... other parameters ... */);
}

// Alternatively, 20 random objects.
for(var i : int; i < objects.length; i++) {
  var object = objects[Random.range(0, 20)];
  Instantiate(object, /* ... other parameters ... */);
}