  We present preliminary measurements of the CP-violating asymmetries in the
decay $B^0\to f_0(980)(\to\pi^+\pi^{-}) K_s^0$. The results are obtained from a
data sample of $209\times10^6$ $\Upsilon(4S) \to B\bar{B}$ decays collected
with the BaBar detector at the PEP-II asymmetric-energy $B$ Factory at SLAC.
  From a time-dependent maximum-likelihood fit we measure the mixing-induced CP
violation parameter $S=-0.95^{+0.32}_{-0.23} \pm 0.10$ and the direct CP
violation parameter $C=-0.24\pm 0.31 \pm 0.15 $, where the first errors are
statistical and the second systematic.
