It is good practice to use Option Explicit and declare all variables.
In worksheet event code "Target" is the active cell.
Qualify all ranges with the parent sheet (and the workbook if there is more than one).
The following code is untested but should be close to what you want...
'---
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Dim myActiveCell As String
Dim myFormula As String

myActiveCell = Target(1).Address(False, False)
myFormula = Sheets("CTD").Range(myActiveCell).FormulaR1C1
If InStr(1, myFormula, "=IF(ISERROR", vbTextCompare) Then
Sheets("Data Entry").Select
Else
Sheets(Array("Data Entry", "CTD")).Select
End If
End Sub
'---
Jim Cone
Portland, Oregon USA .
http://www.mediafire.com/PrimitiveSoftware .
(Determine Colors (excel add-in) - in the free folder)




"Phrank"
wrote in message
...
I tried the Worksheet_Change event, and that's no good because it
initiated the macro every time I even selected a cell. There are only
two sheets in each workbook. ...well, there's actually a 3rd worksheet
(Notes) with notes as to what to do under certain circumstances. This
3rd sheet is helpful, too, with my code, because if for some reason
someone wants to access the CTD sheet, all they need to do is click on
the Notes tab to deselect the other two tabs, then the can select the
CTD tab alone. That part works well. I just need it to be able to
look at the analagous cell in the 2nd tab and press on with the macro.
For some reason, it's working when tested outside of the
Worksheet_SelectionChange event, but not working inside the event.
Thanks.
Frank