function insert_mp3($length, $user_id) {
		$this->db->insert("mp3".AP_PROJECT_NAME, array("length" => $length, "user_id" => $user_id));
		return $this->db->insert_id();
	}
}
<div style="border:1px solid #990000;padding-left:20px;margin:0 0 10px 0;">

<h4>A PHP Error was encountered</h4>

<p>Severity: Warning</p>
<p>Message:  Cannot modify header information - headers already sent by (output started at /var/www/theatrologia.su/html/system/application/models/mp3.php:113)</p>
<p>Filename: helpers/url_helper.php</p>
<p>Line Number: 541</p>

</div>