The LoginName control displays a user's login name if the user has logged in using ASP.NET membership. Alternatively, if your site uses integrated Windows authentication, the control displays the user's Windows account name.
To add a LoginName control to a page
Drag the LoginName control from the Toolbox panel to your page.
To set properties that determine the appearance of the LoginName control, use the Tag Properties panel.
For a full description of all LoginName control properties, see LoginName Members in the MSDN library.