I don't think there's a function to check whether or not the selected item is a groundtile. Without that check people could remove walls, groundtiles, ladders, and so on. You could put all IDs in an array like this {1337, 1338, 1339}, if anyone feels like it, just post the array with all the IDs here and I'll gladly make the script. But it's too much work for me at least.