我对wordpress中导入的searchform有点问题。我们已在此处导入searchform：http://www.campingsosflores.com/en/所有代码都在wordpress插件中运行。

使用以下代码：

    <?php

    function netbooking_searchform($content){

        $GLOBALS["content"] = $content;

        // Function to read a default value in case of error 
        $INPUT = function($param, $default = "", $prefix = true){
            $key = $prefix ? \'netbooking_searchbox_\'.$param : $param;
            return isset($GLOBALS["content"][$key]) ? $GLOBALS["content"][$key] : $default;
        };

        $language = $INPUT(\'language\', \'it\', false);
        $lang = substr($language, 0, 2);
        $cryptedID = $INPUT(\'crypted_id\', \'OiAmpE15aWU=\', false);
        $mod = $INPUT(\'mod\', \'v\', false);

        // Search form sections to be shown
        $displayOptions = array();
        $displayOptions[\'show_arrival_date\'] = "#datefromlabel {display:none;} #datefromvalue {display:none;}";
        $displayOptions[\'show_departure_date\'] = "#datetolabel {display:none;} #datetovalue {display:none;}";
        $displayOptions[\'show_number_of_persons\'] = "#numpeoplelabel {display:none;} #numpeoplevalue {display:none;}";
        $displayOptions[\'show_type\'] = "#structuresnameslabel {display:none;} #structuresnamesvalue {display:none;}";

        // Create CSS using parameters from the form 
        $css = "";
        foreach ($displayOptions as $key => $option) {
            $toShow = $INPUT($key, "on");
            if (isset($toShow) && $toShow != "on"){
                $css .= $option;
            }
        }

$customlabel = \'Bambini (4 - 10 anni)\';

if ($lang == \'en\') $customlabel = "Children (4 - 10 Years)"; // Language String for label



        // Get searchform HTML from WebService
        $api = \'https://webserverlink.com/p/\'.$cryptedID.\'/it/index.php\';
        $query = http_build_query([
            \'type\' => \'p\',
            \'returnmod\' => \'xml\',
            \'id\' => $cryptedID,
            \'cmd\' => \'searchform\',
            \'l\' => substr($language, 0, 2),
            \'mask\' => \'1111110\',
            \'mod\' => $mod,
            \'lblchildren\'=> $customlabel,
            **\'age_1\' => \'4\',** // THE ISSUE IS HERE: This is not added to the link when I click on submit button
            \'nocss\' => \'0\'

        ]);
        $searchform_html = file_get_contents($api. \'?\' . $query );
        $searchform_html = utf8_decode($searchform_html);
        // DOM Parsing
        libxml_use_internal_errors(true);
        $dom = new DOMDocument;
        $dom->loadHTML($searchform_html);
        $xpath = new DOMXPath($dom);
        $booking = $dom->getElementById(\'booking\'); 
        //$booking->removeChild($booking->firstChild); // ... #booking has a first child we don\'t know about...

        // Utility Fuction
        $appendAttribute = function($dom, $element, $attribute_name, $value){
            $attribute = $dom->createAttribute($attribute_name);
            $attribute->value = $value;
            $element->appendChild($attribute);
        };
        $createStyleElement = function($dom, $css_str) {
            $appendAttribute = function($dom, $element, $attribute_name, $value){
                $attribute = $dom->createAttribute($attribute_name);
                $attribute->value = $value;
                $element->appendChild($attribute);
            };
            $style_node = $dom->createElement(\'style\', $css_str);
            $appendAttribute($dom, $style_node, \'type\', \'text/css\');
            return $style_node;
        };
        $createLinkElement = function($dom, $url) {
            $appendAttribute = function($dom, $element, $attribute_name, $value){
                $attribute = $dom->createAttribute($attribute_name);
                $attribute->value = $value;
                $element->appendChild($attribute);
            };
            $link_node = $dom->createElement(\'link\');
            $appendAttribute($dom, $link_node, \'rel\', \'stylesheet\');
            $appendAttribute($dom, $link_node, \'type\', \'text/css\');
            $appendAttribute($dom, $link_node, \'href\', $url);
            return $link_node;
        };

        // New styles to add
        //$defaultStyle = $createStyleElement($dom, $cssOptions[\'default\']);
        $cssCleanerStyle = $createLinkElement($dom, "http://yui.yahooapis.com/3.18.1/build/cssreset-context/cssreset-context-min.css");
        $customStyle = $createStyleElement($dom, $css);
        $googleFontsLink = $createLinkElement($dom, "https://fonts.googleapis.com/css?family=Alegreya|Alegreya Sans|Anonymous Pro|Archivo Narrow|Arvo|BioRhyme|Bitter|Cabin|Cardo|Chivo|Cormorant Garamond|Crimson Text|Domine|Eczar|Fira Sans|Gentium Basic|Inconsolata|Karla|Lato|Libre Baskerville|Libre Franklin|Lora|Merriweather|Montserrat|Neuton|Old Standard TT|Open Sans|PT Sans|PT Serif|Playfair Display|Poppins|Rajdhani|Raleway|Roboto|Roboto Slab|Rubik|Source Sans Pro|Source Serif Pro|Space Mono|Work Sans");
        $netbookingStyle = $booking->firstChild;
        $booking->removeChild($booking->firstChild); // remove to add later

        // styles added from last to first (cause only "insertBefore" exist here...)
        $toInsert = [$googleFontsLink, $customStyle, $netbookingStyle, /*$defaultStyle, */$cssCleanerStyle];
        foreach ($toInsert as $element) {
            $booking->insertBefore($element, $booking->firstChild);
        }

?>


    <div class="yui3-cssreset mod<?= $mod;?>">
        <?= $dom->saveHTML();?>
    </div>

<?php };

?>

\'age_1\' => \'4\', // 问题就在这里：当我点击提交按钮时，这个值并没有添加到链接中。

有人能帮我理解我错在哪里？非常感谢。