  We apply Dijkgraaf-Witten invariant over an semiproduct of abelian groups to
show that, if the $k/\ell$-surgery along a knot $K$ results in a small Seifert
3-manifold with multiplicities $a_1,a_2,a_3$, then many constraints on
$k,a_1,a_2,a_3$ can be read off from the Alexander polynomial of $K$.
