Warning on new replies during typing

[Webrunner]

Hi all,
I recently converted my site from smf to vB.
In SMF there was a nice feature that warns the user when he is posting a new reply that there where new posts during the time he was typing the reply, so he can change the reply and respond to the new replies.
So : i read a thread and hit the "new reply". Then i post the reply and the system reloads to the advanced post screen with a warning: "There have been new replies to this thread since you started typing. Do you want to adjust your reply?"
Then a user can adjust the reply and post it.

My questions are:
1. Does a mod or feature like this exist in vB?
2. If not, who is willing to create it. (i am willing to donate something for it, as long as it will be made publicly available)

My users really miss that feature so i hope someone can help me.