  We present results on the chiral and deconfinement properties of the QCD
transition at finite temperature. We performed calculations using asqtad and
HISQ/tree actions using lattices with temporal extent N_tau=6, 8 and 12
allowing to control the approach to the continuum limit. We analyze the chiral
transition in terms of universal O(N) scaling functions. From peaks in the
scaling functions we perform a simultaneous continuum extrapolation for
HISQ/tree and asqtad to derive the critical temperature, T_c= 157 +/- 6 MeV.
