[AccessD] Clear the display in a combo box

Hi,

I know this should be easy, but I'm not getting it.  I have a combo box, 
I make a selection from the list, I click a button that opens another 
form based on my selection in the combo box.  So far, so good.  I close 
the second form and return to the form with the combo box on it.  I want 
the box to be empty of the choice last made.  That is, I want the form 
with the combo box to appear the way it does before it gets used.  I 
don't want the previous selection to appear in the textbox portion of 
the combo box.  What action or method do I want?  And should it be 
called in the On Activate event?

Thanks,
Tina