Develop a Mac Application

This is a project we made in ASP.NET. Its an examination system made in Visual Studio 2008 using a MySQL database. Please do take a look at it and suggest improvements. Also, if the project is vulnerable to any security threats, please do ping us back. I hope you will like our attempt at coding this application. Features- User first needs to supply valid credentials to begin the test. Randomly chooses 5 questions from a database of 10 questions. The test is a timed test, admin can change the duration of the test before it begins in the code. Test-taker can leave a question un-answered and come back to the question (if time permits) using the ‘Previous’ and ‘Next’ Buttons. Code Details- 1. Login is authenticated against a MySQL database. 2. AJAX is used for the timer, allowing only the timer label to postback to the server each second. 3. Use of the Random class to generate 5 questions out of the 10 in the database. 4. Session Management using Cookies and Session Variables. 5. Use of javascript in the master-page to prevent the ‘Back’ navigation from a page (clearing the cache) [Would love your suggestions on an alternative to this] 6. Once the 5 questions are chosen randomly, they are held in a DataTable. This is then held in a Session Variable to hold the values during postbacks.