PHP/Smarty Image upload

Need a image upload function which integrates into existing code for a Message Board. Current code uses PHP with smarty templates and updates a MySQL database. Image needs to be uploaded with a unique name based on message title and message ID that will be created when image uploaded i.e. silver_teapot_345.jpg. This needs to go into directory on our server /messageImg If a message is uploaded we need to pass 1 to our db (msgImage) field so we know that message has an image. The 345 part of the name would be the unique message ID (msgID) This would be best found by getting last previous message ID and adding 1 Easy job