  We demonstrate top-gate tunable Josephson junction like behavior in the two
dimensional electron gas at the LaAlO$_3$-SrTiO$_3$ interface. A combination of
global back-gating and local top-gating is used to define the junctions,
providing an efficient way for much finer spatial control over the properties
of the interface, as compared to back-gating alone. The variation of critical
currents and zero bias resistances with temperature shows that the junctions
behave like short, overdamped weak links. This technique could be an important
tool to illuminate the nature of superconductivity in the LaAlO$_3$-SrTiO$_3$
interface system.
