title: Corona SDK drawing lines using circles
body: <p>I have this code to draw a line on the screen using display.newCircle. it works perfectly but
  as i draw more it will be more unstable and leaks memory.
  How can i keep this optimized.
  The problem is only on the device.
  Here is the code</p>
  
  <pre><code>local background = display.newRect( 0, 0, 480, 800 )
  
  local lines = {};
  local i = 1;
  local strokeWidth = 20;
  local R = 150;
  local G = 100; 
  local B = 50;
  
  local function drawALine(event) 
      if event.phase == "began" then
      elseif event.phase == "moved" then
  
          lines[i] = display.newCircle(event.x, event.y, strokeWidth, strokeWidth);
          lines[i]:setFillColor( R,G,B );
  
      elseif event.phase == "ended" then
      end     
  end
  Runtime:addEventListener("touch", drawALine)
  </code></pre>
  
  <p>Any help?</p>