404 'url fom/index' not found on server error

Code:
<h3 class='headerstyle'>Registration Form</h3>

<p>Please complete the following form:</p>



&lt;?php echo $this->validation->error_string; ?&gt;

&lt;?php echo form_open('form/index'); ?&gt;



  <p><label for="username">Username: </label><br />&lt;?php echo form_input($username); ?&gt;</p>

  <p><label for="password">Password: </label><br />&lt;?php echo form_input($password); ?&gt;</p>

  <p><label for="name">Name: </label><br />&lt;?php echo form_input($name); ?&gt;</p>

  <p><label for="address">Address: </label><br />&lt;?php echo form_input($address); ?&gt;</p>

  <p><label for="city">City: </label><br />&lt;?php echo form_input($city); ?&gt;</p>

  <p><label for="state">State: </label><br />&lt;?php echo form_input($state); ?&gt;</p>

  <p><label for="zipcode">Zipcode: </label><br />&lt;?php echo form_input($zipcode); ?&gt;</p>

  <p><label for="phone">Phone: </label><br />&lt;?php echo form_input($phone); ?&gt;</p>

  <p><label for="email">Email: </label><br />&lt;?php echo form_input($email); ?&gt;</p>

  <p><label for="url">URL: </label><br />&lt;?php echo form_input($url); ?&gt;</p>

  <p><label for="status">Status: </label><br />&lt;?php echo form_input($status); ?&gt;</p>

  <p><label for="dateB">Date Start: </label><br />&lt;?php echo form_input($dateB); ?&gt;</p>

  <p><label for="dateE">Date End: </label><br />&lt;?php echo form_input($dateE); ?&gt;</p>

  

&lt;?php echo form_submit('submit', 'Submit'); ?&gt;

&lt;?php echo form_close(); ?&gt;