Scratch

well i'm making this game where there a loads of different shapes moving about everywhere but you have to catch the circle in under 60 seconds. i have already made the backgrounds for the different levels however i cannot make the levels work because they keep clashing with each other. here's what i have done for the first level...

when [space v] key pressed
repeat until <<key [up arrow v] pressed?>>
  glide [1] secs to x : [200] y : [129]
  wait [0.1] secs
  glide [1] secs to x : [37] y : [129]
  wait [0.1] secs
end 

for the second level i have done...

when [up arrow v] key pressed
repeat until <<key [down arrow v] pressed?>>
  glide [0.5] secs to x : [200] y : [129]
  wait [0.1] secs
  glide [0.5] secs to x : [37] y : [129]
  wait [0.1] secs
end

please help me, how do you stop them from clashing with each other??