There is a function, StrConv(). It takes 2 arguements, the string, and the
case. For the case, there are 3 options you will use, 1 (UPPER), 2 (lower),
3 (Proper). The VB constants are vbUpper, vbLower, vbProper.
In your case, you'd want to put something in the BeforeUpdate of the field
like this:
Me.Fieldname=StrConv(Me.Fieldname,vbProper)