Well, well, well ... finally you Euro-dudes are alive and awake eh ? Leaving us North American boys to mind the store while you go nodding off - lol [Wink]

The ThreeState property changes the valid return values from the CheckBox.Value like this:

Without ThreeState:

0 - Unchecked
1 - Checked

With ThreeState

0 - Unchecked
1 - Checked
2 - Undefined

-Shawn