switch ($_POST['class'])
{
        case 'program':
                $class = 1;
                break;
        case 'link':
                $class= 2;
                break;
        default:
                $class =1;
                break;
}
<input type="radio" name="class" value="1" /><br />
<input type="radio" namee="class" value="2" /><br />