/**
 * Generate the HTML of the dropdown which holds the list of offered years for
 * a given class.
 */
function makeYearsOfferedHTML($subject_id, $year)
{
    $html = '<select>';
    $years_offered = CourseRoadDB::getYearsClassOffered($subject_id);
    foreach ($years_offered as $year_offered) {
        $year_range = makeYearRange($year_offered);
        $html .= "\n\t<option value='{$year_offered}'";
        $html .= $year_offered === $year ? " selected='true'" : '';
        $html .= ">{$year_range}</option>";
    }
    $html .= "\n<select>";
    return $html;
}