I compile this source. May be it will be useful for others.
Private Sub Workbook_BeforeSave(ByVal SaveAsUI As Boolean, Cancel As Boolean)
Dim wSht As Worksheet
Dim cel_Warning, cel_Cond1, cel_Cond2 As Range
Dim allwShts As Sheets
Dim cel As Range
Dim i As Integer
Cancel = False
Set allwShts = Worksheets
For Each wSht In allwShts
Set cel_Warning = wSht.Range("IT2")
Set cel_Cond1 = wSht.Range("IU2")
Set cel_Cond2 = wSht.Range("IV2")
For i = 1 To 20
If Not IsEmpty(cel_Warning(i)) Then
If Not cel_Cond1(i).Value = cel_Cond2(i).Value Then
a = MsgBox(wSht.Name + Chr(13) + cel_Warning(i))
Cancel = True
End If
End If
Next i
Next wSht
If Cancel = True Then
a = MsgBox("File will not be saved!")
End If
End Sub