VB - Permutation nachweisen

Function is_perm(ByVal a As String, ByVal b As String) As Boolean
    If a.Length <> b.Length Then Return False

    Dim ax, bx As Byte
    For Each c In a
        ax += CByte(Val(c))
    Next

    For Each c In b
        bx += CByte(Val(c))
    Next

    If ax <> bx Then Return False

    Dim al, bl As New ArrayList
    For Each c In a
        al.Add(c)
    Next
    al.Sort()

    For Each c In b
        bl.Add(c)
    Next
    bl.Sort()

    For x As Byte = 0 To al.Count - 1
        If al(x) <> bl(x) Then Return False
    Next

    Return True
End Function