Now that you have a list of appointment times from the professor stored in a file, write the scripts to allow a student to select a time from that list. You will need two scripts for the students. The first script will build a form from the data file. The second script will process the form and assign the student to that time.
Make your form a bit nice looking. You don't have to make it beautiful with graphics and color. But do try the break the appointments up by day, instead of just listing them straight down the page. Your form will need a textbox for the student's name. The student can only pick one time, so the appointment times will be radioboxes.
There are two difficult problems to solve.
1) Only list times that are available.
2) Order the times.
Your form processing script should make sure the student entered a name. How you reserve the time for that student is up to you. Maybe you store the timeslots and names in one file. Or maybe you have one file of appointment times and a second file of reservations.
Create a script that the professor can use to view all the appointment times. This one should be fairly simple.
If you want a challenge, sort the appointments. Another challenge would be to break up the appointments by day and highlight today's appointments.
Submit your three scripts via email. Remember to use an appropriate subject on your message.