full text search and how to underline keyword in results

Hi there, I am trying to write a php script to perform a full text search on a mysql db. I do a match against... and it digs out some results out of the db. There are 2 problems: 1. How can I restrict the results to e.g. 100 characters, but to make sure the keyword is within this 100 characters? 2. Is it possible with php to underline the keyword inside the search results. This might be more tricky. Thank you for any help on that, Andy