Quicktags on all textarea.. Not working on plugin?

I want to put a couple of quicktags/buttons on a textarea which is outputted by a plugin called user submitted posts. I have given this textarea an unique id and read this on the Quicktags documentation:

• Run quicktags(settings) to initialize it, where settings is an object containing up to 3 properties:
• settings = {
• id : 'my_id', the HTML ID of the textarea, required
• buttons: '' Comma separated list of the names of the default buttons to show. Optional.
• Current list of default button names: 'strong,em,link,block,del,ins,img,ul,ol,li,code,more,spell,close';
• } *
• The settings can also be a string quicktags_id. *
• quicktags_id string The ID of the textarea that will be the editor canvas
• buttons string Comma separated list of the default buttons names that will be shown in that instance.

Than, I put this in my functions.php:

?php
add_action('admin_print_footer_scripts','my_admin_print_footer_scripts');
function my_admin_print_footer_scripts()
{
?
script type="text/javascript"/* ![CDATA[ */

    var id = "myID"; // this is your metabox's textarea id

    settings = {
        id : id,
        buttons: 'strong,em,link' 
    }

    quicktags(settings);

/* ]] *//script
?php } ?

The problem: nothing shows up.

PS: I already looked here: Use quicktags toolbar on any textarea

Can someone make a suggestion?