Contact form sending even when unfilled

The contact form works, but emails are sent even when one or none of the requirements are filled. The error message shows up though. Here’s the default contact form code:

                    <?php 
                    if(isset($_POST['submitted'])) { 
                        if(isset($_POST['myname']) && isset($_POST['email'])) {
                            if((trim($_POST['myname']) != "" ) && (trim($_POST['email']) != "" )) { ?>
                                <p class="bg-success"><?php _e('Thanks for contacting us!', 'wp-simple' ); ?></p>
                            <?php } else { ?>
                                <p class="bg-danger"><?php _e('Please enter the required fields (marked with *).', 'wp-simple' ); ?></p>
                            <?php 
                            }
                        }
                    }
                    if(isset($_POST['submitted'])) {
                        $venture_contact_recipient_email = nimbus_get_option('contact-mailto');
                        $venture_contact_sender_email = nimbus_get_option('contact-mailfrom');
                        if($venture_contact_recipient_email != '' && $venture_contact_sender_email != '') {
                            extract($_POST);
                            $blog_name = get_bloginfo('name');
                            $message = "Name: $myname
Email: $email
Company: $website
Comments: $comments
                            ";
                            $headers = 'From: '.$blog_name.' <'.$venture_contact_sender_email.'>' . "\r\n";
                            wp_mail($venture_contact_recipient_email, 'Contact Form', $message, $headers);
                        }
                    }
                    ?>