  The elastic properties of the Zr$_{50}$Cu$_{40}$Ag$_{10}$ metallic alloy,
such as the bulk modulus $B$, the shear modulus $G$, the Young's modulus $E$
and the Poisson's ratio $\sigma$, are investigated by molecular dynamics
simulation in the temperature range $T=250-2000$ K and at an external pressure
of $p = 1.0$ bar. It is shown that the liquid-glass transition is accompanied
by a considerable increase in the shear modulus $G$ and the Young's modulus $E$
(by more than $50\%$). The temperature dependence of the Poisson's ratio
exhibits a sharp fall from typical values for metals of approximately
$0.32-0.33$ to low values (close to zero), which are characteristic for brittle
bulk metallic glasses. Non-monotonic temperature dependence of the longitudinal
and transverse sound velocity near the liquid-glass transition is also
observed. The glass forming ability of the alloy is evaluated in terms of the
fragility index $m$. As found, its value is $m\approx64$ for the
Zr$_{50}$Cu$_{40}$Ag$_{10}$ metallic glass, that is in a good agreement with
the experimental data for the Zr-Cu-based metallic glasses.
