In the vicinity of the QCD phase transition, critical fluctuations have been
predicted to lead to non-statistical fluctuations of particle ratios, depending
on the nature of the phase transition. Recent results of the NA49 energy scan
program show a sharp maximum of the ratio of K+ to Pi+ yields in central Pb+Pb
collisions at beam energies of 20-30 AGeV. This observation has been
interpreted as an indication of a phase transition at low SPS energies. We
present first results on event-by-event fluctuations of the kaon to pion and
proton to pion ratios at beam energies close to this maximum.Comment: 4 pages, 4 figures, Quark Matter 2004 proceeding