Adding / Dropping Users and Roles to multiple dbs

-- adding users and roles to multiple databases
exec sp_msforeachdb @command1 ='use ? CREATE USER [domain\userorgroup] FOR LOGIN [domain\userorgroup] exec sp_addrolemember N''db_datareader'', N''domain\userorgroup'''

-- dropping users and roles to multiple databases
exec sp_msforeachdb @command1 ='use ? exec sp_droprolemember N''db_datareader'', N''domain\userorgroup'' DROP USER [domain\userorgroup]'