Web app development with following req

Question

Hi,
 
i am new to .net i got one task which is i am unable to do it...please help me out from this...task is like this
Need to develop a ASP .NET Website, which has the following two sections:
1. A text box where user can type a message and hit the broadcast button.
2. Where all the messages being broadcast by any user can be seen(real time message feed, new messages should appear without need of reloading the page/hitting a button).
 

 
Thanks & Reagards,
 
sree.