Get An Error On A Sample Code

This is a sample code from an MSDN help site. I copied it and pasted into an open new query. I tried to execute it and got two errors:

USE AdventureWorks;
GO
DECLARE @tablename sysname
SET @tablename = N'Person.AddressType'
table_loop:
IF (@@FETCH_STATUS <> -2)
BEGIN
SELECT @tablename = RTRIM(UPPER(@tablename))
EXEC ('SELECT ''' + @tablename + ''' = COUNT(*) FROM '
+ @tablename )
PRINT ' '
END
FETCH NEXT FROM tnames_cursor INTO @tablename
IF (@@FETCH_STATUS <> -1) GOTO table_loop
GO

The errors are:

Msg 208, Level 16, State 1, Line 1
Invalid object name 'PERSON.ADDRESSTYPE'.

Msg 16916, Level 16, State 1, Line 9
A cursor with the name 'tnames_cursor' does not exist

The database is connected. Table Person.AddressType is a part of it.

What is wrong?

Thanks.