excel vba function Rank2

Function RANK2(value As Double, R As Range, order As Integer) As Integer
Dim a(1000) As Double
Dim n As Integer
Dim i As Integer
Dim k As Integer
Dim tam As Double
n = 0
For i = 1 To R.Rows.Count
    If n > 0 Then
        For k = 1 To n
         If R.Cells(i, 1) = a(k) Then
            GoTo tiep
         End If
        Next k
    End If
   
    n = n + 1
    a(n) = R.Cells(i, 1)
tiep:
Next i
For i = 1 To n - 1
    For k = i + 1 To n
        If a(i) > a(k) Then
        tam = a(i)
        a(i) = a(k)
        a(k) = tam
        End If
    Next k
Next i

For i = 1 To n
    If value = a(i) Then
    If order = 1 Then
    RANK2 = i
    Else
    RANK2 = n - i + 1
    End If
   
    End If
Next i

End Function