Where is the Advanced Editing button?

There is no Advanced Editing button in WP version 2

Scroll down the write post screen and you should see the additional sections – they can be opened by clicking on the + icon eg custom fields.

ok, but how I can Displaying Custom Fields ? What file need to be changed?

In the write posts page, below the post editor is a blue section labeled “Custom Fields”. If there’s a little “+” symbol there click it to open up that section.

There’s your custom fields.

Thamks HandySolo, but it’s not that the problem: I enter the text to the field titled Key and after inthe field Value, but after submit in the article not show this. why?
I’ve read it need modify the Loop and adding the tag:

<?php the_meta(); ?>

but where? in which file? and how I can?

Have a look at your theme’s index.php file.

A good portion of that is The Loop.

Look for something like: <?php the_content(); ?> and try adding your code somewhere in that vicinity.

excuse for my bad english

I’ve solved!
I’ve open the file:
ROOT/wp-content/themes/default/index.php

and I’ve added after this:
<?php if (have_posts()) : ?>
<?php while (have_posts()) : the_post(); ?>:

this code:
<?php the_meta(); ?>

now are showed the custom field.

Thanx all!