  In this report, we present a preliminary measurement of the Bs0 mixing
parameter using samples of four partially reconstructed semileptonic Bs0 decays
and one fully reconstructed hadronic decay mode, corresponding to approximately
2.4 fb^{-1} of integrated luminosity. We perform an unbinned likelihood fit to
the proper decay length and obtain Dms = 18.53 +- 0.93 (stat.) +- 0.30 (syst)
ps^{-1}$.
