' lehvenshsteinsche distance
' http://de.wikipedia.org/wiki/Levenshtein-Distanz
Function match (str1, str2)
    Dim Matrix (), str1len, str2len, i, j, cost, m1, m2, m3

    If (Not ((IsNull (str1) Or IsNull (str2)))) Then
    
        str1len = Len (str1)
        str2len = Len (str2)
        ReDim Matrix (str1len + 1, str2len + 1)
    
        ' populate the matrix
        For i=0 To str1len
            Matrix(i, 0) = i
        Next
        For j=0 To str2len
            Matrix(0, j) = j
        Next

        For i=1 To str1len
            For j=1 to str2len
               
 If (Mid (str1, i, 1) = Mid (str2, j, 1)) Then
               
     cost = 0
               
 Else
               
     cost = 1
               
 End If
            
               
 m1 = Matrix (i-1, j) + 1
               
 m2 = Matrix (i, j-1) + 1
               
 m3 = Matrix (i-1, j-1) + cost

               
 If ((m1 <= m2) And (m1 <= m3)) Then 
               
     Matrix (i, j) = m1
               
 End If
               
 If ((m2 <= m1) And (m2 <= m3)) Then 
               
     Matrix (i, j) = m2
               
 End If
               
 If ((m3 <= m2) And (m3 <= m1)) Then 
               
     Matrix (i, j) = m3
               
 End If
            Next
        Next

        match = Matrix(str1len - 1, str2len - 1)

    Else
        match = 667
    End If

End Function