How to make circle moving within screen in Pascal?

Question

When the left key pressed, the circle moved left but then disappear from the screen. How to keep it moving within the screen only? This is the Pascal code
https://code.sololearn.com/cKDiVDupS0Nu/?ref=app

Answer 1

>Pascal
Now this is a name I haven't heard in a while.
Try outputting ScreenWidth() and x to console when you move - maybe ScreenWidth outputs a value too big?

Answer 2

BlazingMagpie the task give me a hint that the edge of the left screen is X0 but im not sure how to use it.