Using Windows XP Eccel 2003

On a UserForm there are only one ListBox and one OK button.
I would like to change the width of the UserForm, the width of the ListBox
and the position of the OK button,
depending on the largest element in the ListBox (depending on the variable
atl).

I'm using this code:

UserForm2.Width = atl * 158 / 31 + 80
UserForm2.ListBox2.Width = atl * 158 / 31 + 5
UserForm2.OKknop.Left = atl * 158 / 31 + 25

When I use Show to activate UserForm2 , the width of the UserForm and the
position of the OK button are changed, but not the width of the ListBox!
Why not?

Any hint is very welcome!

--
met vriendelijke groetjes