Oops..If your data cannot be defined you can use the below code to validate
this before Save. If you are new to macros set the Security level to
low/medium in (Tools|Macro|Security). 'Launch VBE using short-key Alt+F11. On
the left treeview double click 'This Workbook '. Drop down and select
BeforeSave event. Paste this code. Save.
Private Sub Workbook_BeforeSave(ByVal SaveAsUI As Boolean, Cancel As Boolean)
If Trim(Worksheets("Sheet1").Range("A1")) <> "" Then
If Trim(Worksheets("Sheet1").Range("A2")) = "" Then
Worksheets("Sheet1").Range("A2").Activate
MsgBox "This cell cannot be blank"
Cancel = True
End If
End If
End Sub