Moves the borders of sections around. SECTION is which section's border. UDLR = Up, Down, Left, or Right border. SPEED is what amount the border should move.
UDLR borders 0 = Top border 1 = Bottom border 2 = Left border 3 = Right border
You can use this to make autoscrolling in potentially weird ways.
//Autoscroll to the right in section 3, by moving the screen's left and right borders to the right PushScreenBoundary,3,2,0,0,0,1 PushScreenBoundary,3,3,0,0,0,1