List-View Error! **SOLVED**

OK folks, heres another one i cant figure out:

I have a form which contains three ListViews.

I used the gotFocus method to perform some action. Every thing works fine, while I have the ListViews filled with data.

But if my ListViews have no Data at all, the got focus method always creates an error:

Heres my sourcecode:
VB Code:
Private Sub lstview_GotFocus()
 
On Error GoTo lstview_GotFocus_Err:
 
focus = "lstview" ' focus is a Form variable
 
lstview_GotFocus_Err:
    'Critical Error
    giRC = CriticalMsgBox(Err.Number, Err.Description, Me.Name & "_lstview_GotFocus") ' this is a function which contains the actual msgbox
 
End Sub
Does anyone know why this function runs into the error-clause?

Thanx in advance;

Stephan