I have a form with a listbox on it. Whenever I leave the form and return to the form I want to update the listbox with this requery command. Where should I put the command so that this can happen?

I was wondering where to stick the following two commands -
THISFORM.lstTube_tries.Requery
THISFORM.Refresh

When I leave the main form, I go to another form that I can use to add to the listbox on the first form, but when I return from the second form the listbox does not show the changes made on the second form. For some reason, the Requery is not occurring upon return to the main form. But if I press Prev or Next button, the listbox does show the changes.

What to do? Thanks for the advice.