WordPress 3 Twenty Ten Change Headers

<?php

$themename = 'your theme name';

/** Tell WordPress to run child_theme_setup() when the 'after_setup_theme' hook is run. */
add_action( 'after_setup_theme', 'child_theme_setup' );

if ( !function_exists( 'child_theme_setup' ) ):
function child_theme_setup() {

        // Header Images are now in Child Themes Directory
        define( 'HEADER_IMAGE', get_bloginfo('stylesheet_directory') .'/images/header.png' );

        // Change the header Height here if you need to
        define( 'HEADER_IMAGE_HEIGHT', apply_filters( 'twentyten_header_image_height', 75 ) );

    /* From Aaron Jorbin http://aaron.jorb.in/ */
        function jorbin_remove_twenty_ten_headers(){
                unregister_default_headers( array(
                        'berries',
                        'cherryblossom',
                        'concave',
                        'fern',
                        'forestfloor',
                        'inkwell',
                        'path' ,
                        'sunset')
                        );
        }
        add_action( 'after_setup_theme', 'jorbin_remove_twenty_ten_headers', 11 );


        // Add our own custom headers packaged with the theme. in the theme template directory 'images/headers/'
        register_default_headers( cms_theme_headers() );
}
endif;


/* Build the Header Array from the theme headers */
// No need to code the headers just loop through the folder and return a list
function cms_theme_headers() {
        global $themename;
    $list = array();
        $imagepath = STYLESHEETPATH .'/images/headers/';
        $imageurl = get_bloginfo('stylesheet_directory');
    $dir_handle = @opendir($imagepath) or die("Unable to open $path");
    while($file = readdir($dir_handle)){
        if($file == "." || $file == ".."){continue;}
        $filename = explode(".",$file);
        $cnt = count($filename); $cnt--; $ext = $filename[$cnt];
        if(strtolower($ext) == ('png' || 'jpg')){
                  if (!strpos($file, '-thumbnail') > 0) {
                                $header = array(
                                        'url' => $imageurl .'/images/headers/' .$file,
                                        'thumbnail_url' => $imageurl .'/images/headers/' .$filename[0] .'-thumbnail.' .$ext,
                                        'description' => __( $filename[0], $themename )
                                );
                                array_push($list, $header);
                  }
        }
    }
    return $list;
}