function check_group(frm) {
	var message = '';
	
	var name = frm.name.value;
	var username = frm.username.value;
	var password = frm.password.value;
	var re_password = frm.re_password.value;

	var id_calendar = parseInt(frm.id_calendar.value);

	if (!name && !message) {
		message = 'Please enter group name';
		frm.name.focus();
	}

	if (!username && !message) {
		message = 'Please enter user name';
		frm.username.focus();
	}

	if (!password && !message) {
		message = 'Please enter password';
		frm.password.focus();
	}

	if (password != re_password && !message) {
		message = 'Please confirm your password';
		frm.re_password.focus();
	}
	
	if (!id_calendar && !message) {
		message = 'Please choose session date';
		frm.id_calendar.focus();
	}

	if (message) {
		alert(message);
		return false;
	} else {
		return true;
	}
}