if you enter some data on a page and accidentally you forget one of the required fields and yet submit that page , the page is posted to the server and when the page returns saying that one of the required fields is missing, if you see all that data which you previously entered intact then such a page is viewstate enabled, else go on entering that data again [ no viewstate] Thats it. Regards Sam

viewstate is allows the state of objects(serialize)to be stored in a hiddenfield on the page. viewstate is transported to the client and back to the server,and not stored on the server or any other external source.it is used to retain the server side objects between  postback implementation

advantages

1. don't reserve memory on clientside or serverside

2. it reduces the burden of the developer because developer needn't write manual coding

drawbacks

we will  send large volumes of data from client to server

if u hav any doubts u  send me a mail to [email protected]