How to create a msg before saving a excel Sheet

[Swapnanjali]

When I change this code ;I am getting some error..

Sub Workbook_BeforeSave(ByVal SaveAsUI As Boolean, Cancel As Boolean)
Dim rowcount As Long
Dim lstRow As Long
Dim i As Long
Sheet1.Activate
lstRow = Range("A" & Rows.Count).End(xlUp).Row
For i = 4 To lstRow
If Range("A" & i).Value <> "" Then
If Range("B" & i) = "" Or Range("C" & i) = "" Or Range("d" & i) = "" Or Range("E" & i) = "" Or Range("f" & i) = "" Or Range("G" & i) = "" Or Range("h" & i) = "" Or Range("i" & i) = "" Or Range("j" & i) = "" Or Range("k" & i) = "" Or Range("l" & i) = "" Or Range("m" & i) = "" Or Range("n" & i) = "" Or Range("o" & i) = "" Or Range("p" & i) = "" Or Range("q" & i) = "" Or Range("u" & i) = "" Or Range("v" & i) = "" Or Range("w" & i) = "" Or Range("x" & i) = "" Or Range("y" & i) = "" Or Range("z" & i) = "" Or Range("AA" & i) = "" Or Range("AB" & i) = "" Or Range("AC" & i) = "" Or Range("AD" & i) = "" Or Range("AE" & i) = "" Then
MsgBox "you have to fill the Blank row", vbInformation, "MsgBox"

Sheet1.Activate
lstRow = Range("B" & Rows.Count).End(xlUp).Row
If Range("B" & i).Value <> "" Then
If Range("C" & i) = "" Or Range("d" & i) = "" Or Range("E" & i) = "" Or Range("f" & i) = "" Or Range("G" & i) = "" Or Range("h" & i) = "" Or Range("i" & i) = "" Or Range("j" & i) = "" Or Range("k" & i) = "" Or Range("l" & i) = "" Or Range("m" & i) = "" Or Range("n" & i) = "" Or Range("o" & i) = "" Or Range("p" & i) = "" Or Range("q" & i) = "" Or Range("u" & i) = "" Or Range("v" & i) = "" Or Range("w" & i) = "" Or Range("x" & i) = "" Or Range("y" & i) = "" Or Range("z" & i) = "" Or Range("AA" & i) = "" Or Range("AB" & i) = "" Or Range("AC" & i) = "" Or Range("AD" & i) = "" Or Range("AE" & i) = "" Then
MsgBox "you have to fill the Blank row", vbInformation, "MsgBox"

Cancel = (Len(Sheets("Sheet1").Range("J" & i).Value) = 0)
   If Cancel Then MsgBox "Please fill in Column J!"
  

Cancel = True
Exit Sub

End If
End If
End If
Next i
End Sub