Save Screenshot to a Folder [VS] (better method)

-- [screenie] (name given to the definition script)
-- saves a png screenshot if a path is specified else saves screenshot to be used for next save game image!
-- checks if file exists before saving - loops check until file doesn't exist![better method]
-- syntax: "createScreenshot(path)" or "createScreenshot(path, {flags=1, clear = true|false})"
-- ref: http://wiki.visionaire2d.net/index.php?title=CreateScreenshot

-- declare an incrementing variable (increment the variable by 1 with "count = count +1")
local count = 0

-- saves a png screenshot to the screenshot folder with a numer amended to the end based on current count value!
function save_screenie_to_path()
 local filename = 'screen_' .. count .. '.png'
 local f = io.open('screenshots/' .. filename, 'r')
 -- * --
 if f then
  print('-- * --') -- comment this out if you don't want it!
  print(filename .. ' already exists!') -- comment this out if you don't want it!
  count = count +1
  f:close()
  check_save_screenie()
else
  createScreenshot('screenshots/' .. filename)
  print('-- * --')
  print(filename .. ' has been saved to the screenshots folder!')
  count = count +1
 end
end

-- loops to check if next screenshot_x.png exists else save screenshot to folder!
function check_save_screenie()
 save_screenie_to_path()
end