switch to current database in SP procedure

Use master
go
create proc sp_TableCount as
select count(*) TableCount from sys.tables
where type_desc='USER_TABLE'
GO

use master
exec sp_TableCount

use test
exec sp_TableCount

you always get the TableCount from the Master database.
how can I switch to current database in SP procedure ?

use db_name() ??

--SQL 2005

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hello