Some C#, PHP and AJAX work

Hey! I have an application that connects to the server trough mysql to show that the application is online. This is checked on a website that have php and ajax. The application is written in C#. This is what it does now. 1. Student insert candidate ID. The application connects to the database once to download some information. Then it reconnects to the database every minutte. Imagine 35.000 students doing this to the same server :D 2. The php page checks whether the application has sent a 1 or 0 to the database and give a message to the invigilator. What i wan't done. 1. The student insert candidate ID. The application connects to the databse once and download some information. It then sends a txt file to the server with the following. Candidate ID, number 1 for online, and date and time. 2. The php checks the candidate ID. Then it checks if it finds the number 1. Then it checks the time. If the php page has not recived a new time within 1 minutte it gives a offline message to the inviglator that the student is offline. That easy! Future PHP projects will be given. I have some small tasks. Skype is required and you need to be online most of the day. Discussions only trough skype. Best regards.