whenever auto insert row than auto enter a formula in specific cell

hello 
i have made a sheet with automatic row insertion if column f is less than column h. now i want that whenever the row is inserted than a formula should be entered in the row which is inserted below with formula (column f - column h) of the above row .

Example:-say if i have entered in row 4 of column f value 10 and row 4 of column h value 9 than a row is automatically inserted just below row 4 , now i want that in new row which is inserted just below column 4 say Row 5 is inserted , in that row 5 column f i want a formula that is f4-h4 so that the balance value may come.

Code:

Option ExplicitPrivateSub Worksheet_Change(ByVal Target As Range) Const SALES_PWD = "123" Dim i AsLongIf Target.Column = 8 And Target.Row > 3 ThenIf Cells(Target.Row, "K").Value <> 0 ThenIf MsgBox("Add new row?", vbYes) Then
                Updating = True
                ActiveSheet.Unprotect Password:=SALES_PWD 
                Rows(ActiveCell.Row & ":" & ActiveCell.Row).Insert 
                Cells(ActiveCell.Row, ActiveCell.Column) = Cells(ActiveCell.Row + 1, ActiveCell.Column)            Cells(ActiveCell.Row + 1, ActiveCell.Column) = "" For i = 1 To 5 
                    Cells(ActiveCell.Row, i).Formula = Cells(ActiveCell.Row - 1, i).Formula Next i 
                CopyCells 7 
                CopyCells 9 
                CopyCells 10 
                CopyCells 11 
                Cells(ActiveCell.Row, 8).Select 
                ActiveSheet.Protect DrawingObjects:=True, Contents:=True, Scenarios:=True, Password:=SALES_PWD 
                Updating = FalseEndIfEndIfEndIf
Sub CopyCells(ColNum AsLong) 
    Cells(ActiveCell.Row - 1, ColNum).Select 
    Selection.Copy 
    Cells(ActiveCell.Row + 1, ColNum).Select 
    ActiveSheet.Paste End Sub
End Sub

thanking you in advance

regards

vipul jain