Insert Rows Between Blocks Of Information

I have used some code that Kris gave me a couple of weeks ago and changed it to insert a row between each block of information. Have I got it right?

Sub InsertRows()
Dim lRow As Long
Dim r As Long
lRow = Range("A" & Rows.Count).End(xlUp).Row
Application. ScreenUpdating = False
Columns("M").Insert
[m3] = "temp1"
Range("M4:M" & lRow) = "=LEFT(A4,5)"
For r = Cells(Rows.Count, 1).End(xlUp).Row To 2 Step -1
If Cells(r, 13) <> Cells(r - 1, 13) Then Rows(r).Insert Shift:=xlDown
Next r
Columns("M:N").Delete
Application.ScreenUpdating = True

Application.DisplayAlerts = False
ActiveWorkbook. SaveAs Filename:= _
"H:HOME imcEXCELCOUPON_COUNT5_MAYREFORECAST.xls", FileFormat:=xlNormal _
, Password:="", WriteResPassword:="", ReadOnlyRecommended:=False, _
CreateBackup:=False
Application.DisplayAlerts = True
ActiveWindow.SelectedSheets.PrintOut copies:=1
End Sub