No External Links In Signature - Please Read For Explanation

[rishel]

Not sure if this has been done.

I am wanting to know if someone has made or could make a script, that disallows links to work in a signature file on a forum, if they lead anywhere else other than the site the forum is on.

For example:

If John Doe was at www.abc.com and he had a signature file in his posts that had a link to www.xyz.com the link would not work.

But if John Doe was at www.abc.com and he had a signature file in his posts that had a link to something else on www.abc.com it would work.

This is to prevent spamming of other sites in the sig file in posts, they can print it out, but not have a link.

Any feedback would be greatly appreciated.