the code is pseudocode
Yep - realised that after re-reading your original. I just saw the {'s. My post edited.

Taking the mouse outside the image does not cancel the Click. Becasue you clicked on the Image, that control will receive Mouse events until you release the mouse. The Click event is only raised when you release the Mouse OVER the image.

I don't understand where you're having a problem. You mouse down on the Image, the displayed pic changes. The Image will receive the next Mouse Up so you don't need to track mouse moves on the userform. Or perhaps I'm misunderstanding