  It is shown that the operator $B(C) = Tr [P \exp i \tilde{g} \oint
\tilde{A}_i(x) dx^i]$ constructed with the recently derived dual potential
$\tilde{A}(x)$ and a coupling $\tilde{g}$ related to $g$ by the Dirac
quantization condition satisfies the correct commutation relation with the
Wilson operator $Tr [P \exp ig \oint A_i(x) dx^i]$ as required by 't Hooft for
his order-disorder parameters.
