Detach all databases on a server

use master
go

exec master..sp_MSForEachDB '
if(''?'' not in (''master'',''msdb'',''tempdb'',''model''))
begin
print ''use master''
print ''go''
print ''EXEC master.dbo.sp_detach_db @dbname = ''''?'''', @keepfulltextindexfile=N''''true''''''
print ''go''
end
'
go