vertical scroller Perspective camera bounds

Getting Started Newbie Questions
#1

hello, i’m making a infinite vertical scroller and using a Perspective camera (from CalebP) to track object as it going up. but i need to camera track only when object is going up and when object fall from bottom screen to stop track. i can’t figure how to set bounds or what have i missing.  

this is my code:

in scene:show i set bounds 

 camera:setBounds(centerX,centerX, -screenH, centerY)   camera:setFocus(hero)   camera:track()

and have  enterFrame function (levelsize = -display.contentHeight)

&nbsp;function setLevelBound() &nbsp;&nbsp;if (hero.y \< levelsize) then &nbsp; &nbsp;&nbsp;&nbsp;--print("SET BOUNDS NEW") &nbsp;&nbsp;&nbsp;camera:setBounds(centerX,centerX,levelsize\*2, centerY) &nbsp;&nbsp;&nbsp;levelsize = levelsize \* 2 &nbsp;&nbsp;end &nbsp;&nbsp;--if (platformS[first].y \< hero.y) then &nbsp;&nbsp;&nbsp;--print("--x--") &nbsp;&nbsp;&nbsp;--camera:setBounds(centerX,centerX,levelsize, hero.y) &nbsp;&nbsp;--end &nbsp;end

 i have comented out if stat. because i don’t know if i’m on right track with this. It is working going up.