  Lattice calculations of the form factors for the charm semileptonic decays D
to K l nu and D to pi l nu provide inputs to direct determinations of the CKM
matrix elements |V(cs)| and |V(cd)| and can be designed to validate
calculations of the form factors for the bottom semileptonic decays B to pi l
nu and B to K l l-bar. We are using Fermilab charm (bottom) quarks and asqtad
staggered light quarks on the 2+1 flavor asqtad MILC ensembles to calculate the
charm (bottom) form factors. We outline improvements to the previous
calculation of the charm form factors and detail our progress. We expect our
current round of data production to allow us to reduce the theoretical
uncertainties in |V(cs)| and |V(cd)| from 10.5% and 11%, respectively, to about
7%.
