Shoutbox

Here's what you can do:

1. Store your own email address in a global variable, for example:

   code:

   ---

   var sAllowedEmail = "myself@hotmail.com";

   ---

2. In the OnEvent_Signin event, check the received first parameter (Email) against the allowed email address.
   
3. If the email addresses match, do nothing.
   
4. If the email addresses do not match, use Messenger.Signout() to make this unwanted user sign out. Display a friendly(?) toast message with MsgPlus.DisplayToast to inform them why he/she has just been signed out.

Although this will work great, it won't actually prevent them to sign in: they'll simply be signed out as soon as they are signed in, which is just as effective (and annoying) in my opinion.

Please, try not to ask us for copy-paste-ready code, this script request is very easy to achieve when you simply have a look at the scripting documentation. The best way to learn programming is by trying new things out yourself!