Media button Thickbox content doesn't work everywhere

Question

Please, understand that I'm new to wordpress and php.

I added a media button to my media buttons in the admin by adding the following code to functions.php file:

function add_custom_media_button() {
    echo '<a href="#TB_inline?inlineId=custommedia_container" id="insert-my-media" class="button thickbox">Add custom media</a>';
}
add_action('media_buttons', 'add_custom_media_button', 15);

add_action( 'admin_footer',  'add_inline_popup_content' );
function add_inline_popup_content() {
    $cu = wp_get_current_user();
    $cusername = $cu->user_login;
    echo '<div id="custommedia_container" style="display:none;">';
    echo '<iframe class="mediaselectoriframe" title="Archivado" width="100%" height="99%" title="cosas" src="http://nephila.cloudapp.net/GAdEWeb/wpsearch.aspx?wpuser=' . $cusername . '&wplang=' . $clocale . '" frameborder="0"></iframe>';
    echo '</div>';
}

Now, this is working on Create Post page, but is not anywhere else.

I can see my button in Edit post, Create page and Edit page, but there's nothing inside the thickbox.

Answer 1

I ended up solving this by changing my two functions to only one, and setting the "button" to show the iframe directly, like this:

function add_custom_media_button() {
    $cu = wp_get_current_user();
    $cusername = $cu->user_login;
    $clocale = get_locale();
    echo '<a href="http://nephila.cloudapp.net/GAdEWeb/wpsearch.aspx?wpuser=' . $cusername . '&wplang=' . $clocale . '&TB_iframe=true&width=800&height=600" id="insert-my-media" class="button thickbox">Add custom media</a>';
}
add_action('media_buttons', 'add_custom_media_button', 15);