SRM7 : Where to get logoff button configuration and source code

Hello Experts,

Could you please give information where to get configuartion for logoff button displayed at top corner of the main screen in SRM7.

i ) Is there any webdynpro component or component configuration exists for that logoff button? If exists, then please provide the name.

ii) Can i configure the logoff button depending on user id , say for one user it will be hidden and for some user it will be displayed?

Thanks,

Partha