any pointers on best way to use php to create online schedule of trips that has x amount of seats available, then site visitor can purchase one or more seats on the trip by clicking the puchase button and then taken to paypal, then need to get info back from paypal with confirmation of purchase so can then have the available number of seats on the trip be reduced by how many seats they purchased. Is this something that there might be some code for somewhere and is it the proper way to solve the online booking / scheduling /payment system, thanks much in advance for any help...