Try pasting this into the ThisWorkbook object (right-click on the Excel icon to the left of the File menu and select 'View Code').
Private Sub Workbook_SheetChange(ByVal Sh As Object, ByVal Target As Excel.Range)HTH
If Target.Column <> 8 Then Exit Sub
Application.EnableEvents = False
If Target.Offset(0, -4).Value = "" Then
Target.Value = ""
MsgBox "You must make an entry in the 'D' column of this row first!"
Application.EnableEvents = True
EDIT: Added a little extra help.
««« ¤ Richie ¤ »»»
[ This Message was edited by: Richie(UK) on 2003-01-30 10:03 ]