Disabling an Option Menu item

[Edwin Gore]

Is it possible? I am letting a user import a delimited text file, then I snag the first line of it and display each item with an option menu underneath it. Each item on the option menu maps to a field on a card. When the user selects an item from the menu (thereby mapping that item from the text file to a card field) I want to disable that menu item, so the user can only map one field in the text file to one field on the card.

When I try this, I just get a paren in front of the item, and it remains selectable.

I can't use a compbo box, because the user isn't allowed to type anything in, I can't use a pop-up or drop down menu because I want the user's selction to remain beneath the field they are mapping...

I'm at a loss.