سيكون هكذا :
Private Sub trns2_AfterUpdate()
On Error GoTo Err_trns2_Click
If IsNull(mnth2) Then
MsgBox "اختر الشهر"
DoCmd.CancelEvent
Exit Sub
End If
Dim stDocName As String
if trns2 = "ccp" then
stDocName = "VIREMENTCCP"
else
stDocName = "rptTransBnk"
end if
DoCmd.OpenReport stDocName, acPreview
Exit_trns2_Click:
Exit Sub
Err_trns2_Click:
If Err.Number = 2501 Then
Resume Exit_trns2_Click
Else
MsgBox Err.Description
Resume Exit_trns2_Click
End If
End Sub