Create error messages based on entries in 2 cells

[dori2o]

I have a sheet which calculates charges due on an account.


I have a box at B10 which can be completed to offer a discount.


I have a dropdown which references to box D5 where a user can select a 'Loyalty Discount' (shows "1" for no discount, then either "2"or "3" for the level of discount.


The customer cannot have both, therefore I am looking for a vba (unless this can be done in validation) code that will trigger if an entry is entered into B10 and the loyalty discount is already given at D5. Or where the loyalty discount is selected from the dropdown and and entry already exists at B10.

Unfortunately I cannot provide an example of the sheet as it contains confidential information.


As always your help is greatly appreciated.


Thanks

 

[mumps]

I'm not sure if I understood correctly but try this macro in the worksheet code module:

Private Sub Worksheet_Change(ByVal Target As Range)
    If Intersect(Target, Range("B10,D5")) Is Nothing Then Exit Sub
    Application.EnableEvents = False
    Select Case Target.Address
        Case "$B$10"
            If Range("D5") <> "" Then
                MsgBox ("Loyalty Discount already exists in cell D5.")
                Target.ClearContents
                Application.EnableEvents = True
                Exit Sub
            End If
        Case "$D$5"
            If Range("B10") <> "" Then
                MsgBox ("Discount already exists in cell B10.")
                Target.ClearContents
                Application.EnableEvents = True
                Exit Sub
            End If
    End Select
    Application.EnableEvents = True
End Sub

 

[dori2o]

I'm not sure if I understood correctly but try this macro in the worksheet code module:

Private Sub Worksheet_Change(ByVal Target As Range)
    If Intersect(Target, Range("B10,D5")) Is Nothing Then Exit Sub
    Application.EnableEvents = False
    Select Case Target.Address
        Case "$B$10"
            If Range("D5") <> "" Then
                MsgBox ("Loyalty Discount already exists in cell D5.")
                Target.ClearContents
                Application.EnableEvents = True
                Exit Sub
            End If
        Case "$D$5"
            If Range("B10") <> "" Then
                MsgBox ("Discount already exists in cell B10.")
                Target.ClearContents
                Application.EnableEvents = True
                Exit Sub
            End If
    End Select
    Application.EnableEvents = True
End Sub

Thanks.

Unfortunately I've just tried it and it fires whenever any entry is made in B10

It also doesn't fire when D5 is changed by selecting the dropdown options.

I've been trying different options such as using a helper column, with an IF/AND statement in F1 as follows:

=IF(AND(B10>0,D5>1),TRUE,FALSE)

The formula works but I'm now struggling to understand how to get data validation/macro to fire when the
cell changes to True