Wrong action from form

[eluser]pigfox[/eluser]
In my views/contact_form.php I have:

$attributes = array('id' => 'contactform');
echo form_open('contact/send', $attributes);

Those lines generate:
<form action="http://www.mydomain.com/index.php/contact/send" method="post" id="contactform">
But I'm using .htaccess to eliminate the "index.php" so the url fails.
I need to have:
<form action="http://www.mydomain.com/contact/send" method="post" id="contactform">
Any clue how I can fix this?

[eluser]Christopher Blankenship[/eluser]
Update the following config/config.php

Code:

$config['index_page'] = "index.php";

to the following

Code:

$config['index_page'] = "";

[eluser]pigfox[/eluser]
That worked.
Thank you!