This should work for the newer versions of Access ...
If IsLoaded("MyForm") then
<your code>
End if
Function IsLoaded(MyFormName) As Boolean
' Accepts: a form name
' Purpose: determines if a form is loaded
' Returns: True if specified the form is loaded;
' False if the specified form is not loaded.
If CurrentProject.AllForms(MyFormName).IsLoaded Then
IsLoaded = True
Exit Function
End If
End Function