virtual interfacing of input value

[wa7ed]

Hi,
Is it possible to make a virtual interface represents the value of an input? For example, if we have a program shows the level of a liquid in a tank and we want to represent the level virtually: as the calculated value of the level increases, the level (and color) filled in the tank shown, increases as well.
example:
if the value is 100, the tank ( a rectangular ) will be shown full and green. If it is 0, will be shown empty and red.

[wa7ed]

Is it that difficult to do such a thing? Or the question wasn't clear ?
!