<?php

    global $CONFIG;
    
    $subject = get_input('subject');
    $begin = get_input('begin');
    $end = get_input('end');
    
    $url = $CONFIG->wwwroot . "pg/poster/courses/?subject=" . $subject;

    if (get_input('reset_button'))
        forward($url);

    if (!($begin) && !($end)) {
        forward($url);
    }
    
    $begin_timestamp = dateIntoTimestamp($begin);
    $end_timestamp = dateIntoTimestamp($end);

    if ($begin && $end && ($begin_timestamp > $end_timestamp)) {
        /*translation:The beginning of the period should be smaller than the end*/
        register_error(elgg_echo("koolielu:message_error_period_beginning_larger_than_end"));
        forward($url);
    }

    $url .= "&begin=" . $begin_timestamp . "&end=" . $end_timestamp;

    forward($url);

?>