collectable coins and scroeing system

I need help writing code I'm using java script I got the controls down for a sprite but I can get the random generation of coins to spawn and a score system setup. I also can figure out how to make my sprite stay inside the screen boarder some help would be fantastic

do you have collition detection for the coins

Instead of having your player move around the scene, have the scene move around the player.

screen.drawSprite("player",x,y,20,20) ---> screen.drawSprite("scene_object",x,y,20,20)

This may reverse the controls but its pretty easy to undo that.