"On Error goto" help

[kingzl3y]

well, im creating a tool.
And i've implemented some Error tools (On error goto..and what not)
but i have a problem, If an error occours i want to show a msgbox - once that msgbox has been clicked it then exits the sub
I've tried numerous ammount of ways all fail on me
Someone please enlighten me! pls x[

e.g.

Private Sub cmd1_Click()
On Error GoTo 321
Timer1.Interval = txtTimer.Text
On Error GoTo 123
Timer1.Enabled = True 'Start sending messages
123:
MsgBox "Error123", vbInformation
[B]exit sub[/B] 
321:
MsgBox "Error321", vbInformation
End Sub

*Note to self*
bold tags in vbcode do NOT work.