  Strangeness enhancement has been predicted to be one of the signatures of the
formation of the quark gluon plasma (QGP) and event-by-event fluctuations of
strangeness may reveal the nature of such a phase transition. We report results
for $K/\pi$ fluctuations from Cu+Cu at $\sqrt{s_{NN}}$ = 62.4 and 200 GeV and
Au+Au collisions at $\sqrt{s_{NN}}$ = 62.4, 130 and 200 GeV using the STAR
detector at the Relativistic Heavy Ion Collider. We compare our results with
the results observed in central Pb+Pb collisions at SPS energies at
$\sqrt{s_{NN}}$ = 6.3, 7.6, 8.8, 12.3, and 17.3 GeV. We observe the fluctuation
strength measured at the highest SPS energy point by the NA49 collaboration in
Pb+Pb collisions is similar to our results in Cu+Cu and Au+Au collisions. We
also compare our results with HIJING, a statistical hadronization model and a
multi-phase transport model.
