Theme directory path in wordpress

I saw this website to get the path of the theme where the files are: http://codex.wordpress.org/Function_Reference/get_bloginfo

And I have a form (file register.php) that sends a post to a file (register_proc.php) in the same directory.

<form id = "form" name = "form" method = "post" action = "<?php echo get_option ('template_url');? > /register_proc.php ">

The two files are in: wp-content/themes/theme_name .

But when I submit the link in browser is “http://127.0.0.1/register_proc.php” and it says the file is not found. Why?