function hpbar() --Can anyone help me? (LUA)

-=-=-=-=-=-=-=-=-=-=-=-=-=-
I want a health bar that is put on top of robots like DanKaz' but doesn't react with 1 signals, but instead, with the signal sent to that IN socket. I want to use HP control to show life percentage of a robot. And when it receives a 0 signal, it dissapears/dissipates.

EX: whenever a .67 signal is sent to INX, the health bar shows 67% of the full HP. It can be rounded if you want it to be.