Cell Data Validation

[one_more_cave_dweller]

I would like to require the user to enter a number into a2 before they can enter a number in a1. How can I do this

Thanks ray:

 

[vconfused]

You could use code. Right-click on the Sheet's tab and paste in the following code:

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Selection.Address = "$A$1" And Range("A2") = "" Then
Range("A2").Select
End If
End Sub

You may have to go to Tools->Macro->Security, set the security level to Medium, save the file, close and reopen the file and click Enable Macros. But what it does is if you click A1 (and only A1) and A2 is empty, it select A2. I'm sure there are other ways to do the same thing, but I can't think of a way without code.

 

[vconfused]

You could also use conditional formatting so that the text in A1 is white until you put something in A2, but that wouldn't really help

 

[one_more_cave_dweller]

Isn't there a way to use Data>Validation?

Thanks ray:

 

[one_more_cave_dweller]

 

[swst]

Could have this

In cell A3
=if(A1="","Data has not been entered in cell A1",A2)

Cell A3 would then be used for any ongoing calculations

 

[vconfused]

Data->Validation is used to make sure you enter appropriate values, but it cannot be used to allow/disallow you from entering values.

 

[Todd Bardoni]

Data->Validation is used to make sure you enter appropriate values, but it cannot be used to allow/disallow you from entering values.

Data/Validation most certainly can allow/disallow you from entering values.

Select A1. In Data/Validation choose custom and use this formula:-

=AND(ISNUMBER(A1),ISNUMBER(A2))

Then, uncheck the box that says "ignore blank".

 

[ken2step]

Also....

=ISNUMBER(A2) Uncheck the box "ignore blank"

works as well

 

[Todd Bardoni]

Also....

=ISNUMBER(A2) Uncheck the box "ignore blank"

works as well

Not exactly. The OP specified he wanted numbers entered into A1 and A2. My solution ensures that the user enters a number into A2 and can only enter a number into A1 (if A2 has a number, of course).

Your solution will allow text to be entered into A1.