How to test table locking?

Hi

I have been reading this tutorial to learn how to read/write lock a table.

But I wish to know how do I test it?

I ran the command

LOCK TABLE users WRITE;

The above code should ideally lock the table for reading/writing to other connections. But when I open phpmyadmin in another browser, i can still read the data of that table.

Is there anyway to test if its working?

Database: MySQL 5.1.41-3
Table Type: MyISAM

Thanks in advance