I have add custome multiselect box in course certificate page but multi select data not store in datdabase
$moption = array(
'Java' => 'Java',
'PHP' => 'PHP',
'ASP' => 'ASP'
);
$select = &$mform->addElement('select', 'coursename', 'label for colors', array('red', 'blue', 'green'));
$select->setMultiple(true);
$mform->setDefault('coursename', 0);
$mform->addHelpButton('coursename', 'coursename', 'certificate');