how do i make it so that if a value (any value) isnt entered into a cell, an error message is displayed?

Suppose cells B2:B10 is where you want to begin this. Then choose Data > Validation, and in dialog box select Custom. In the formula area put:


=COUNTA($B$2:$B2)=ROWS($1:1)

and copy down from B2 to B10.

Adjust references as needed.

what does counta do?

It checks to make sure that each cell is filled in (by counting the number of cells in the expanding range) - notice the mixed absolute and relative references. As you copy it down, it will change appropriately so that all cells will require filling.

If this method does not work, post back.

i only need to check that one field has a value in it, not a row or column of cells. also, where do i put the formula?

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If IsEmpty(Range("A1").Value) Then
MsgBox "Please enter data into cell A1"
Range("A1").Select
Exit Sub
End If

End Sub

The above uses VBA to check that cell A1 isn't empty, every time you try and do something. Anything. It will then show the error message and return you to cell A1 until you putt something in it. You could probably then use Data Validation to make sure the correct value is put in.

Andrew H