You should show the form as a Modal dialogue like this:-
Private Sub btn_Search_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_Search.Click
Dim f As New form2()
f.ShowDialog()
...
... Code to process form results
...
f.Dispose()
End Sub
Then your user must close the form2 before using form1 again.
Hope this helps
[EDIT] Don't forget to Dispose a form shown with ShowDialog. - DSK[/EDIT]