  We report on progress of a lattice QCD calculation of the $B\to Dl\nu$ and
$B_s\to D_s l\nu$ semileptonic form factors. We use a relativistic staggered
action (HISQ) for light and charm quarks, and an improved non-relativistic
(NRQCD) action for bottom, on the second generation MILC ensembles.
