Hi Mike,

Try this for beggining:

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Range("B4") < 0 Then
Call Test
ElseIf Range("B4") = 0 Then
MsgBox "a 0 value has been entered!"
Else
End If
End Sub


Sub Test()
MsgBox "Bla Bla Bla"
End Sub

Regards.
Jorge
"Mike" escreveu na mensagem
...
I have a macro that is activated by button. I have a cell b4 that an
operator
must
enter a numerical value greater than zero.
I need a sub that would check the value of cell b4. If the value is
greater
than zero,
then the sub would proceed.
If cell b4 is equal to 0, then a message box would appear telling the
operator
that a 0 value has been entered. Once the operator clicks the OK in the
message
box, an exit sub would be activated and the operator
would be returned to the data entry screen.
thanks for any assistance.