how to show previous rows in datalist in asp.net

Question

hi sir...I am displaying id,message and date in datalist when send button is clicked...that means i am entering message in textbox then send button need to be clicked...if i send button is clicked i am storing that message into db from there i am displaying...for second time if i type message in text box then send button is clicked....so i am getting recently sending message....but i want previous message also how should i get......pls tell me source code......