php - Checkbox Group Array to String Conversion Error -

i have checkbox group array posting arrays, not in email. i'm using code 'implode' arrays:

<?php     if ( !empty($form->data['student']) && is_array($form->data['student'] ) ) {       $session = array();       foreach ( $form->data['student'] $s ) {       $session[] = "<tr><td>{$s['schoosedaym']}</td></tr><tr><td>{$s['sxcarem']}</td></tr>";       }     }     $form->data['session_data'] = implode("\n", $session);     ?> 

does know how can checkbox group arrays post in email?