[AccessD] Trick Needed

Dear List:
 
There are two text boxes on a form.  As  the user keys info into text box 1,
that is, after every key stroke,  I would like the length of the data in
text box 1 to appear  in text box 2.  But I can't find an event that 'knows'
what the current length is in text box 1 until it loses and regains focus.
 
Is there a slick way to get this number?

MTIA
 
Rocky