Firstly, there's a few minor errors:
Has lots of squares which aren't meant to be there.
Two separators instead of one.
And lastly, I tried using it for a few minutes, then was displayed with this:
I restarted the script, no good. Restarted Messenger, no good.
And also, the toast says 'plugin'. It's not a plugin, it's a script.
Apart from that, looks good.