Collision Detection Problem

[Fashoomp]

For my racing game, i am trying to figure out collision. I found a sample code just for movement, and im trying to change it for collision. Its a ball that moves on screen. I drew a line on screen, and was wondering if anyone can show me how to make the ball not able to pass through that line. Heres the code

code:

setscreen ("graphics:800;600,offscreenonly") var x, y : real var vx, vy : real := 0 var key : array char of boolean x := 400 y := 300 loop drawline (maxx div 2, maxy div 2-100, maxx div 2, maxy div 2+100, 7)     Input.KeyDown (key)     if key (KEY_UP_ARROW) then         vy += 0.2     elsif key (KEY_DOWN_ARROW) then         vy -= 0.2     end if     if key (KEY_RIGHT_ARROW) then         vx += 0.2     elsif key (KEY_LEFT_ARROW) then         vx -= 0.2     end if     if key (' ') then         vx := 0         vy := 0     end if     x += vx     y += vy     if x > maxx-5 or x < 0+5 then         vx := -vx         x += vx     end if     if y > maxy-5 or y < 0+5 then         vy := -vy         y += vy     end if     vx *= 0.99     vy *= 0.99     drawfilloval (round (x), round (y), 5, 5, blue)     View.Update     delay (10)     cls end loop

[Carey]

You could use whatdotcolour to check if you are touching the line, or you could check the distance from the line with Math.Distance. If the distance from the line is equal to the radius of your ball then bounce.