Booking System

My client already has a booking system but as its old and most functions have depreciated now my client is needing a new system. The system must be coded using PHP OOP using only code which is not depreciated, for instance explode instead of split etc etc. I am a php developer so i will be checking the code to make sure all is working 100% with no errors within the error logs. The coding must also be secure, making sure all ints are indeed ints, real escaping everything that is needed and using trim and htmlentities when needed. The booking system will go as follows: <!----------------- frontend ------------------!> people will go to booking page. They will select available dates which was setup in the admin area from the calender. When user clicks the date a popup lightbox effect will show and within that the user will then have available time slots which are set within the admin area which, next to each time will be how many people are left in the time slot (drop down selective box), the user then selects how many people they want. Enter details: name, address etc etc. If the user inputs a voucher code then it will generate the booking and go to a thank you page. If the user states pay using paypal then it will take the person to paypal and then after payment is complete it will generate the booking. (must check payment has been sent before generating booking). An email confimation is then sent to admin and to booking user. <!----------------- frontend ------------------!> <!----------------- Backend-------------------!> In the admin area the admin should have a settigns area where the admin should be able to select default times and dates... for instance. They select the days they want to work: monday to saturday, these will be set as default and the days selected will be available on the calender all the time. The admin can then select default time, from 4am - 12am, and again they will be default on default days in-which the user selected. Also within the settings page there needs to be a email input for the admins email address, paypal email so that payments are made through paypal. There also needs to be a input area where admin can input how many people per is allowed per hour. There will be another section where the admin then selects days off, the user can select specific days they do not want to work and that will then take effect on the calender. It will also override the default if it is present. There will also need to be a exception area, this will be where the user can add dates, for instance the admin selects default days are monday to friday, that means no saturdays and sundays show. So on the exception page the admin selects a specific saturday and that will show on the frontend calender. Obviously there will be a bookings page where admin can see all bookings. On this will show by year when bookings are made, when the admin clicks on the year it will show all months of that year where bookings was made, when the admin clicks on the month it will take you to all dates within that month of the bookings. When the admin clicks on the date it will take them to all bookings within that date. If the user clicks on the booking it will show all information of that booking. For instance it will show persons name, address, email, phone number, paid or by voucher, if voucher then it will show voucher code etc etc. <!----------------- Backend-------------------!> This is a replica to what the user already has, i can show a demo of the booking system now but only to people i really think i might use for this project. The bidders must have read all this and quoted the words "ARSENAL FAN" within the hello of the pm messages.