'Calcul de la clé de contrôle
'Calculation of the checksum
For i% = 12 To 1 Step -2
checksum% = checksum% + Val(Mid$(chaine$, i%, 1))
Next
checksum% = checksum% * 3
For i% = 11 To 1 Step -2
checksum% = checksum% + Val(Mid$(chaine$, i%, 1))
Next
chaine$ = chaine$ & (10 - checksum% Mod 10) Mod 10