Twitter checks messages if they are duplicates of the previous and does not accept them a second time.
So for testing you need to generate new messages (=content) each time.
This is documented somewhere at Twitter, but you can also read about on other sites.
Delete your last status update via Twitter web and run the script again. Or include date(‘r’) or md5(mt_rand()) with your status message to generate a different one each time the script is run.
