One way:

Put this in the worksheet code module:

Private Sub Worksheet_Change(ByVal Target As Excel.Range)
Const sPWORD As String = "drowssap"
Dim rArea As Range
Dim rCell As Range
Me.Unprotect Password:=sPWORD
For Each rArea In Target
For Each rCell In rArea
With rCell
.Locked = Not IsEmpty(.Value)
End With
Next rCell
Next rArea
Me.Protect Password:=sPWORD
End Sub

In article ,
MIke wrote:

I have a spreadsheet that I would like the cells to lock after a value has
been entered. Can I do this with a macro or in the sheet code?

Thanks

Mike