Getkey

local bpressed = getkey(str)

Returns a boolean based upon whether a key or key combination as specified by the string str is depressed or not. The key-specifier string str can contain A-Z, 0-9, F1-F12 and ESC, BACK, TAB, ENTER, PAUSE, CAPSLOCK, SPACE, PGDN, PGUP, END, HOME, LEFT, RIGHT, UP, DOWN, PRNSCR, INSERT, DELETE, NUMLOCK, SCROLLLOCK, CTRL, ALT, or SHIFT.

Warning: since getkey is based on GetAsyncKeyState, this function will register a currently depressed key regardless of what application is in the foreground.