Key Press Events In IE?

I'm doing a tutorial from a book to drag and drop elements on a page into a shopping cart. I had everything working fine in IE until I added the function for key presses. What it should do is when 1 is clicked, the first item is moved into the cart, and if I press 1 again the item goes back to where it started.

The function that's giving me problems is keyDrag (at the bottom). I included the other functions in case you need to see them because keyDrag calls them. The error I'm getting in IE is "object expected" and it's at the line marked below in the keyDrag function.

What happens when I press 1 is the item that's supposed to go to the cart appears at the cursor as if I clicked and dragged it. But if I drag it manually into the cart, and then press 1, it will snap back to its original place without problems.

Code:
<script type="text/javascript" language="javascript">
if(isNS) document.captureEvents(Event.MOUSEDOWN | Event.MOUSEMOVE | Event.MOUSEUP);
document.onmousedown = grabIt;
document.onmousemove = moveIt;
document.onmouseup = dropIt;

[Code]...