Shoutbox

I think they all have the same parent thread which means there would be no way to distinguish. Using the script you downloaded before, you can copy a function to get the text from the toast and check if it says "X has sent you a message". Once you have received that and closed it, add the user into an array. As long as you check who the toast is off against the array and only close it if it doesn't appear in the array, it'll be ok. Then you can delete the user from the array when the window is closed so that the toasts show again until you close the window...

Actually sounds pretty complicated, but it's not that difficult to be honest... I may try re-wording this post sometime.

If you can't do it I will have a try, but have a go at it first.