-- rect demo
x=120
y=68
dx=7
dy=4
col=1

cls()
function TIC() 
--Update x/y
 x=x+dx
 y=y+dy
 --Check screen walls
 if x>240-6 or x<0 then
  dx=-dx
  col=col%15+1
 end
 if y>136-6 or y<0 then
  dy=-dy
  col=col%15+1
 end
 --Draw rectangle
 rect (x,y,6,6,col) 
end