Hi Jock,
'======================>>
Private Sub Worksheet_Change(ByVal Target As Range)
Dim rng As Range
Const TestString As String = "xxxx" '<<===== CHANGE
Set rng = Range("A15")
If Not Intersect(rng, Target) Is Nothing Then
Rows("16:20").Hidden = StrComp(rng.Value, TestString, _
vbTextCompare) = 0
End If
End Sub
'<<======================
(1) Copy the above code
(2) Right-click the worksheet tab
(3) Paste the copied code
(4) Alt-F11 to return to Excel
All done!
Now try entering: xxxx or XXXX in A15. This should hide rows, 16-20.
Deleting, or changing A15 should restore rows 16:20 to view.