Remove duplicate rows

Hi.

I have found this at:

http://www.cpearson.com/excel/deleting.htm

Public Sub DeleteDuplicateRows()
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' DeleteDuplicateRows
' This will delete duplicate records, based on the Active Column. That is,
' if the same value is found more than once in the Active Column, all but
' the first (lowest row number) will be deleted.
'
' To run the macro, select the entire column you wish to scan for
' duplicates, and run this procedure.
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''

Dim R As Long
Dim N As Long
Dim V As Variant
Dim Rng As Range

On Error GoTo EndMacro
Application.ScreenUpdating = False
Application.Calculation = xlCalculationManual


Set Rng = Application.Intersect(ActiveSheet.UsedRange, _
                    ActiveSheet.Columns(ActiveCell.Column))

Application.StatusBar = "Processing Row: " & Format(Rng.Row, "#,##0")

N = 0
For R = Rng.Rows.Count To 2 Step -1
If R Mod 500 = 0 Then
    Application.StatusBar = "Processing Row: " & Format(R, "#,##0")
End If

V = Rng.Cells(R, 1).Value
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' Note that COUNTIF works oddly with a Variant that is equal to vbNullString.
' Rather than pass in the variant, you need to pass in vbNullString explicitly.
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
If V = vbNullString Then
    If Application.WorksheetFunction.CountIf(Rng.Columns(1), vbNullString) > 1 Then
        Rng.Rows(R).EntireRow.Delete
        N = N + 1
    End If
Else
    If Application.WorksheetFunction.CountIf(Rng.Columns(1), V) > 1 Then
        Rng.Rows(R).EntireRow.Delete
        N = N + 1
    End If
End If
Next R

EndMacro:

Application.StatusBar = False
Application.ScreenUpdating = True
Application.Calculation = xlCalculationAutomatic
MsgBox "Duplicate Rows Deleted: " & CStr(N)

End Sub

But what i want it to do is to look through two columns like these:

Cat Number

Aa 0001
Aa 0001
Aa 0001
Aa 0001
Aa 0001
Aa 0002
Aa 0002
Aa 0002
Aa 0002
Aa 0003
Aa 0004
Aa 0005
Aa 0005
Aa 0005
Aa 0005
Aa 0005
Aa 0006
Ab 0001
Ab 0001
Ab 0001
Ab 0001
Ab 0001
Ab 0001
Ab 0001
Ab 0001
Ab 0002
Ab 0002
Ab 0002
Ab 0002
Ab 0002
Ab 0003
Ab 0003
Ab 0003
Ab 0003
Ab 0003
Ab 0004
Ab 0004
Ab 0004
Ab 0004
Ab 0005
Ab 0005
Ab 0005
Ab 0005
Ab 0005
Ab 0005
Ab 0005
Ac 0001
Ac 0001
Ac 0001
Ac 0001
Ac 0001
Ac 0001
Ac 0001
Ac 0002
Ac 0002
Ac 0002
Ac 0002
Ac 0002
Ac 0002
Ac 0003
Ac 0003
Ac 0003
Ac 0003
Ac 0003
Ac 0003
Ac 0004
Ac 0004
Ac 0004
Ac 0004
Ac 0004
Ac 0004
Ac 0004


and have a result like this:

Cat Number

Aa 0001
Aa 0002
Aa 0003
Aa 0004
Aa 0005
Ab 0001
Ab 0002
Ab 0003
Ab 0004
Ab 0005
Ac 0001
Ac 0002
Ac 0003
Ac 0004

Is It possible to edit the macro mentioned or is there a complete (better?) way?

Hope you can help me out on this on...

Nicolai