Add code to search.php

Hi
Same issue that I wrote before with no reply
Please, I need to resolve this.
I bought JIG pluggin, and installed it. But in order to get search results I need to:

Add the following code to your theme’s search.php file, after the line where the content wrapper div starts, before any result gets shown with a loop. For your information, the JIG shortcodes will do the following:

this is the code:

<?php
    global $wp_query, $query_string;

    if(!empty($wp_query->query_vars['jig_custom_search'])){
        $jig_custom_search = $wp_query->query_vars['jig_custom_search'];
        $search_value = $wp_query->query_vars['s'];
        echo do_shortcode("If you didn't find what you were looking for, try a new search!<br/><br/>[jig_custom_search_form source=".$jig_custom_search."]<br/><br/>");
        switch ($jig_custom_search) {
            case 'nextgen':
                get_jig(array('ng_search_query' => $search_value));
                break;

            case 'flickr':
                get_jig(array('limit' => '200', 'flickr_search_text' => $search_value, 'flickr_search_user' => '9563763@N08'));
                break;

            default:
                break;
        }

        echo '<style type="text/css">
                .post-content {
                    display: none;
                }
            </style>
            <script type="text/javascript">
                jQuery(".jigErrorMessage").text("No content found.")
            </script>';

        $wp_query = new WP_Query();
        $query_string = '';
    }
?>

So how can I do that. I’m using child theme.