Hi, can anyone please help me, I'd like to verify if cell T5 is > 500 or < -500 and if so, pop up a red msgbox that is 800x600 in size then add 1 to cell T10.

Your help would be very much appreciated

Thank you

The easiest way I guess would be to use a user form instead of a message box (that way you can control the colour, size etc).

the following code assumes you are running the macro from the page with the data on - if not amend the references to cells().value to read

sheets(Your Sheet Name Here in "").cells()

fMsgbox in this example is the custom userform.

If Cells(5, 20).Value > 500 Or Cells(5, 20).Value < -500 Then
    Cells(10, 20).Value = Cells(10, 20).Value + 1
    fMsgbox.Show
End If