PHP & MySQL get value of auto_increment field of new data

Hi folks, The dumb newbie has a question... I use a PHP script to take data from a web form and insert it into a MySQL database. The database has an id field that is AUTO_INCREMENTing and the primary key. I want to be able to retrieve the id field that belongs to the record I just inserted. My first thought was to just pull out the highest value in the id field, but what happens if two people are entering data at the same time? I'm sure this is unlikely, but I would think there would be another way. I also thought about sending a query to match the data just entered, but the only field that would be unique would be a giant text field that is probably not a good idea to perform searches on. Any suggestions? Thanks, -T