how to create online examination system using timer and sql

Question

how to create online examination system using timer with help of java script and sqlserver 2008 

sir I have all ready create a online examination system but problem is their when I choose answer and click button then timer countdown reset for every question. 

sir my question is when I set 30 minute for each subject and exam complete then after that news timer count want to be start for new subject so I kinadly request to you then you provide all code step by step using timer control

if its possible for you then you give me complete code using sql2008 database