How to process data acquired by POST method?

Hello.

I have installed EXEC-PHP plugin which allows me to put PHP scripts into my pages. I created a simple page with the following content:

<?php
echo '<pre>';
print_r($_POST);
echo '</pre>';
?>
<form method="post">
<input type="text" name="name"/>
<input type="submit"/>
</form>

When I open this page, it’s works as intended, showing me the following text:

Array
(
)

and the input form.

When I press the “Submit” button with empty text input field, I get the following:

Array
(
    [name] =>
)

Everything is still excellent. But when I enter some text to the input field and press “Submit”, I’m getting “Sorry, but you are looking for something that isn’t here.”

How to fix this? Where in the WordPress’s code the checking of POST data presence is performed??