Update function in Corona.

Good day! I’m currently new in using Corona SDK. In the Unity Game Engine I can create my own time by using the Update() function and creating my variable like float timer. I would just increment the time in the Update function by adding .2f to the current value. But here in Corona idea how would that work? Thank you!

[lua]

local function Update ()

end

Runtime:AddEventListener(“enterFrame”, Update)

[/lua]

[lua]

local function Update ()

end

Runtime:AddEventListener(“enterFrame”, Update)

[/lua]