how to select data from database one by one on button click

Question

hi,i'm creating a "online examination website", my question is that how to select data from database one by one on button click event.

i'm preparing question page and fetching data on radiobuttonlist using to show answer and a label is used to show question 

but i have problem is that on button click event i have not getting the next question from database,i'm using sql-server to backend.

please any one can send me the c# code to do that this thing.....my emailid "[email protected]"