I want post photo on behalf of my users who logged-in in my website


we are developing a web site where guests will register to log in. After log in, guests will see their photos and see the twitter icon to post the photo (not the link to photo) on their twitter account. Guest will have to enter the twitter credentials in-order to post the photo on their twitter account.

do you have any documentation as describe the steps to do it. More importantly, when my application is posting the photo on behalf of guest, do i get any oAuth token from Twitter. If so, what is the scope of the token. with in the session or forever means do i need to store the token against guest in my DB in order to re use in future posts?

please help and thanks in advance.