Conditional data validation

[hedgie]

Can this be done easily? Cell A2 should contain either N/A if the value of A1 is "NO" or the user should be able to select "yes" or "no" in A2 if the value of A1 is "YES".

 

[bjwillingham]

Set data validation for cell A1 to 'list' with the list values of "Yes,No"

Somewhere, maybe on another tab (to be hidden) put "N/A" in a cell. Name that cell "List1"

Somewhere on that same tab but the values "Yes", "No" in adjacent cells. Name that 2 cell range "List2"

Then insert a name "Lists" and set the refersto =IF(A1="No",list1,list2)

Then set data validation of A2 to list values '=lists'

 

[HalfAce]

Hello hedgie
Here's another idea. Which one to use depends on how the "Yes" / "No" values
are being entered into A1.
First one is for if the entry is being made manually, copy/pasted or via code.
(Works with the Worksheet_Change event.)

Option Explicit
Option Compare Text

Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Address <> "$A$1" Then Exit Sub
Select Case Target.Value
  Case "No"
    With [A2]
      .Validation.Delete
      .Value = "N/A"
    End With
  Case "Yes"
    [A2] = ""
    With [A2].Validation
    .Delete
    .Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, _
      Operator:=xlBetween, Formula1:="Yes, No"
    .IgnoreBlank = True
    .InCellDropdown = True
    End With
  Case Else
    With [A2]
      .Validation.Delete
      .Value = ""
    End With
End Select
End Sub

The second one is for if the value in A1 is not being entered but is actually the
return of a formula.
(Is basically the same but works with the Worksheet_Calculate event.)

Option Explicit
Option Compare Text

Private Sub Worksheet_Calculate()
Select Case [A1].Value
  Case "No"
    With [A2]
      .Validation.Delete
      .Value = "N/A"
    End With
  Case "Yes"
    [A2] = ""
    With [A2].Validation
    .Delete
    .Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, _
      Operator:=xlBetween, Formula1:="Yes, No"
    .IgnoreBlank = True
    .InCellDropdown = True
    End With
  Case Else
    With [A2]
      .Validation.Delete
      .Value = ""
    End With
End Select

In either case you'll only need one or the other and they both get installed the same.
1) Right click the sheet tab and choose View code.
2) Copy/paste the code from here into white pane that is the sheet code module.
3) Press Alt+Q to close the vb editor and get back to your sheet.