Chopping strings

[Anon]

I am displaying news stories on a site. What I want to do with the news story is display only part of it with a link to the full story. I have the link sorted but want to know how to display the first 250 characters, find the next full stop after this and display that as the teaser story.

Any ideas?
Thanks in advance

[[deleted]]

to find the fullstop:

http://www.php.net/manual/en/function.strpos.php

and to get everything left from the fullstop:

http://www.php.net/manual/en/function.substr.php