A protocol is simply a set of rules. It is important to design the protocol before coding the Delphi program or the PHP script.
Think about what we are trying to do. We want the Delphi program to send a day and a month to the PHP script which will then query the MySQL table to obtain the names of all the people who were born on that day and month. We then want the PHP script to send a list of names back to the Delphi program. The list may contain zero or more names.
So we need to send the PHP script a day number and a month number. Let's decide upon the name of the PHP script. We'll call it 'birthdays.php'. Now if you type the following into your web browser you will get a response indicating that you haven't submitted any parameters
The way you submit parameters is to append a question mark and then a name-value pair. Subsequent parameters are prefixed by an ampersand. So our request for a list of names that were born on 24th July would be