title: collision attempt to index global (a nil value)
body: <p>When i try a collision with BCloud1.png bed i get a  attempt to index global 'BCoud1' (a nil value) ?  is there any simple ways to resolve this error ? </p>
  
  <p>i have done this : </p>
  
  <pre><code>function getRandomStar()
      local temp = starTable[math.random(1, #starTable)] -- Get a random star from starTable
      local randomStar = display.newImage(temp.imgpath) -- Set image path for object
  
      if ( temp.imgpath == "BCloud1.png" ) then
      temp.imgpath = "BCloud"..tostring(math.random(1, 3))..".png";
      physics.addBody( BCloud1, { density=3.0, friction=0.5, bounce=0.3 } )
      end
  
      if ( temp.imgpath == "BCloud2.png" ) then
      temp.imgpath = "BCloud"..tostring(math.random(1, 3))..".png";
      physics.addBody( randomStar, "static", { density=.1, bounce=.1, friction=.2, radius=45 } )  
      end
  
      if ( temp.imgpath == "BCloud3.png" ) then
      temp.imgpath = "BCloud"..tostring(math.random(1, 3))..".png";
      physics.addBody( randomStar, "static", { density=.1, bounce=.1, friction=.2, radius=45 } )  
      end
  
      randomStar.myName = "star" -- Set the name of the object to star
      randomStar.movementSpeed = temp.movementSpeed; -- Set how fast the object will move
      randomStar.x = math.random(-30, _W);    
      randomStar.y = -35;
      randomStar.rotation = math.random(0,20) -- Rotate the object
  
      starMove = transition.to(randomStar, {
          time=randomStar.movementSpeed, 
          y=500,
          onComplete = function(self) self.parent:remove(self); self = nil; 
          end
          }) -- Move the star
  end--END getRandomStar()
  
  
  local function onLocalCollision1( self, event )
      if ( event.phase == "began" ) then
  print (" Collision1 ")
      elseif ( event.phase == "ended" ) then
      end
  end
  BCloud1.collision = onLocalCollision1
  BCloud1:addEventListener( "collision", BCloud1.png)
  </code></pre>