  We describe the current status of the MILC collaboration computation of
$f_B$, $f_{B_s}$, $f_D$, $f_{D_s}$ and their ratios. Progress over the past
year includes: better statistics and plateaus at $\beta=6.52$ (quenched),
$\beta=5.6$ ($N_F=2$) and $\beta=5.445$ ($N_F=2$), new runs with a wide range
of dynamical quark masses at $\beta=5.5$ ($N_F=2$), an estimate of the
systematic errors due to the chiral extrapolation, and an improved analysis
which consistently takes into account both the correlations in the data at
every stage and the systematic effects due to changing fitting ranges.
