You can’t turn off cookies in a single page but if you want to turn off the cookies in an application
<sessionState cookieless = "true" />
in web.config file.
Turn off Cookie in your browser – Mozilla FireFox Tools-Options-deselect cookie, if selected.
— OR —
Use the Cookie.Discard Property which Gets or sets the discard flag set by the server. When true, this property instructs the client application not to save the Cookie on the user’s hard disk when a session ends.