Sophisticated Photo Session Reservation Form

I am currently using a PHP based entry form which allows my customers to place a reservation for their photo session on my website (<[login to view URL]>) but I had to manually propose them two or three dates. This entry form relies on FormMail from [[login to view URL]][1] and is working fine, but I would like to enhance it so my customers can directly choose their shooting date/time from a bunch of predefined hours slots. The idea I had in mind was to have these available slots defined somewhere (XML file or in a database) and have the form automatically scan, extract and propose the next available slots to the customer, based on the chosen photo shooting session (which all have different characteristics). ## Deliverables I am currently using a PHP based entry form which allows my customers to reserve their photo session on my website (<[login to view URL]>) This entry form relies on FormMail from [[login to view URL]][1] and is working fine, but I would like to enhance it so my customers can directly choose their shooting date/time from a bunch of predefined availability slots. The idea I had in mind was to have these availability slots defined somewhere (XML file or in a database) and have the form automatically extract and propose the X next available entries to the customer, based on the chosen photo shooting session (which each have different characteristics/properties). Each photo sessions will be defined with a specific Photo Session Code which would allow the form application to find the next available slots and propose them to the customer in the shooting date/hour field. Let's take a concrete example: EFC-15-45-200-1 => Experience F?e Clochette EC-120-90-400-4 => Experience Cendrillon ETM-150-120-600-4 => Experience Top-Model EB-180-150-900-4 => Experience Boudoir Each Photo Session Code contains the Photo Session characteristics/properties, separated by a minus sign ("-"). Based on second example here above (EC-120-90-400), let's see what each of these parts mean: First part (EC) would be the Phooting Session ID (which will inform me what the customer has ordered) Second part (120) would mean that each confirmed reservation should allocate 120 minutes for this shooting session (which will in turn influence the proposal made to next customer) Third part (90) would mean that each confirmed reservation should display a hourly range of 90 minutes (like "30 Septembre de 14:00 ? 15:30") Four part (400) would correspond to the normal price of that photo session (needed for requesting the payment through PayPal) Fifth part (4) would correspond to the number of different date proposals to provide for such a photo session (attention: 1 date can still generate many time proposals, like shown here below) Regarding the Availabilities in which the script should search for to find appropriate time slots to propose to the customer, it should look like this: Valid for Date From To ********* ************ ******** ******** EFC 30/09/2011 08:00 10:00 EFC 30/09/2011 10:00 12:00 EFC 30/09/2011 13:00 15:00 EFC 30/09/2011 15:00 17:00 EC/ETM 05/10/2011 14:00 18:00 * 07/10/2011 14:00 19:00 !EFC/EB 08/10/2011 14:00 18:00 EB 10/10/2011 17:00 20:30 * means valid for any Photo Session ID EC/ETM means valid for defined Photo Session ID !EFC/EB means not valid for defined Photo Session ID If user selects Photo Session "F?e Clochette", with ID EFC-15-45-200-1, the form should propose following options (four options because 4 different availability records found, all having the same date): 1) 30 septembre 2011, de 08:00 ? 08:45 2) 30 septembre 2011, de 10:00 ? 10:45 3) 30 septembre 2011, de 13:00 ? 13:45 4) 30 septembre 2011, de 15:00 ? 15:45 If user selects Photo Session "Experience Boudoir", with ID EB-180-150-900-4, the form should propose following options (max first 4 available dates, which correspond to only 2 options in this specific case): 1) 7 octobre 2011, de 14:00 ? 16:30 (150 minutes) 2) 10 octobre 2011, de 17:00 ? 19:45 Each time the reservation form allocates a day/time slot for a photo session, that should be recorded so this day/time slot won't be proposed anymore. Either the form application should update the above available time slots accordingly, or it should store the reserved slot somewhere else, in which case the reservation form will have to cross check availability by looking at 2 places (originally defined slots - already used slots). I don't care how you implement this, as long as it works correctly. Of course, the reservation form should never propose a date in the past (would have no sense). Moreover, you should update the corresponding available time slot **only once the payment has been successfully confirmed and sent by mail to me, which means that you should check that PayPal payment has been done before confirming the appointment to the user and updating the corresponding availability entry.** I will of course provide the full source code I am using until now. Please make me a proposal for doing such a development for me.