upload image in a meta box

im trying to implement uploading via a meta box without using the media manager, but i want it to add as a post attachment.

im currently doing it just uploading and saving to the server.

<?php

define("THUMB_DIR", WP_CONTENT_DIR . '/plugins/meta-upload/thumbs/'); 
define("THUMB_URL", WP_CONTENT_URL . '/plugins/meta-upload/thumbs/'); 

// this needs to be implemented

function fileupload( $label ) { ?>
<tr>
    <td class="left_label"> <?php
        echo $label; ?>
    </td>
    <td>
        <form name="uploadfile" id="uploadfile_form" method="POST" enctype="multipart/form-data" action="<?php echo $this->filepath.'#uploadfile'; ?>" accept-charset="utf-8" >
            <input type="file" name="uploadfiles[]" id="uploadfiles" size="35" class="uploadfiles" />
            <input class="button-primary" type="submit" name="uploadfile" id="uploadfile_btn" value="Upload"  />
        </form>
    </td>
</tr>  
 <?php
}

//this needs to be added too

function fileupload_process() { 
$uploadfiles = $_FILES['uploadfiles'];

if (is_array($uploadfiles)) {

    foreach ($uploadfiles['name'] as $key => $value) {

        // look only for uploded files
        if ($uploadfiles['error'][$key] == 0) {

            $filetmp = $uploadfiles['tmp_name'][$key];

            //clean filename and extract extension
            $filename = $uploadfiles['name'][$key];

            // get file info
            // @fixme: wp checks the file extension....
            $filetype = wp_check_filetype( basename( $filename ), null );
            $filetitle = preg_replace('/.[^.]+$/', '', basename( $filename ) );
            $filename = $filetitle . '.' . $filetype['ext'];
            $upload_dir = wp_upload_dir();

            /**
             * Check if the filename already exist in the directory and rename the
             * file if necessary
             */
            $i = 0;
            while ( file_exists( $upload_dir['path'] .'/' . $filename ) ) {
                $filename = $filetitle . '_' . $i . '.' . $filetype['ext'];
                $i++;
            }
            $filedest = $upload_dir['path'] . '/' . $filename;

            /**
             * Check write permissions
             */
            if ( !is_writeable( $upload_dir['path'] ) ) {
                $this->msg_e('Unable to write to directory %s. Is this directory writable by the server?');
                return;
            }

            /**
             * Save temporary file to uploads dir
             */
            if ( !@move_uploaded_file($filetmp, $filedest) ){
                $this->msg_e("Error, the file $filetmp could not moved to : $filedest ");
                continue;
            }

            $attachment = array(
                'post_mime_type' => $filetype['type'],
                'post_title' => $filetitle,
                'post_content' => '',
                'post_status' => 'inherit'
            );

            $attach_id = wp_insert_attachment( $attachment, $filedest );
            require_once( ABSPATH . "wp-admin" . '/includes/image.php' );
            $attach_data = wp_generate_attachment_metadata( $attach_id, $filedest );
            wp_update_attachment_metadata( $attach_id,  $attach_data );
        }
    }
}
}

add_action('admin_menu', "post_upload_box_init");
add_action('save_post', 'post_save_thumb');

function post_upload_box_init() {
    add_meta_box("post-thumbnail-posting", "Dark Toob Thumbnail", "post_upload_thumbnail", "post", "advanced");

}

function post_upload_thumbnail() {
    global $post;
?>
<script type="text/javascript">
    document.getElementById("post").setAttribute("enctype","multipart/form-data");
    document.getElementById('post').setAttribute('encoding','multipart/form-data');
</script>

<?php
    $thumb = get_post_meta($post->ID, 'custom_thumbnail',true);

    if ( $thumb )
    {
?>
<div style="float: left; margin-right: 10px;">
    <img style="border: 1px solid #ccc; padding: 3px;" src="<?php echo THUMB_URL . $thumb; ?>" alt="Thumbnail preview" />
</div>
<?php
    }
    else
    {
?>
<div style="float: left; margin-right: 10px; width: 200px; height: 150px; line-height: 150px; border: solid 1px #ccc; text-align: center;">Thumbnail preview</div>
<?php } ?>

<div style="float: left;">
    <p>
        <label for="thumb-url-upload"><?php _e("Upload via URL, or Select Image (Below)"); ?>:</label><br />
        <input style="width: 300px; margin-top:5px;" id="thumb-url-upload" name="thumb-url-upload" type="text" />
    </p>    
    <p>
        <p><label for="thumbnail"><?php _e("Upload a thumbnail"); ?>:</label><br />
        <input id="thumbnail" type="file" name="thumbnail" />
    </p>
    <p><input id="thumb-delete" type="checkbox" name="thumb-delete"> <label for="thumb-delete"><?php _e("Delete thumbnail"); ?></label></p>

    <p style="margin:10px 0 0 0;"><input id="publish" class="button-primary" type="submit" value="<?php _e("Update Post"); ?>" accesskey="p" tabindex="5" name="save"/></p>
</div>

<div class="clear"></div>
<?php
}

function post_save_thumb( $postID )
{
global $wpdb;

// Get the correct post ID if revision.
if ( $wpdb->get_var("SELECT post_type FROM $wpdb->posts WHERE ID=$postID")=='revision')
    $postID = $wpdb->get_var("SELECT post_parent FROM $wpdb->posts WHERE ID=$postID");

if ( $_POST['thumb-delete'] )
{
    @unlink(THUMB_DIR . get_post_meta($postID, 'custom_thumbnail', true));
    delete_post_meta($postID, 'custom_thumbnail');
}
elseif ( $_POST['thumb-url-upload'] || !empty($_FILES['thumbnail']['tmp_name']) )
{
    if ( !empty($_FILES['thumbnail']['name']) )
        preg_match("/(.(?:jpg|jpeg|png|gif))$/i", $_FILES['thumbnail']['name'], $matches);
    else
        preg_match("/(.(?:jpg|jpeg|png|gif))$/i", $_POST['thumb-url-upload'], $matches);

    $thumbFileName = $postID . strtolower($matches[0]);

    // Location of thumbnail on server.
    $loc = THUMB_DIR . $thumbFileName;

    $thumbUploaded = false;

    if ( $_POST['thumb-url-upload'] )
    {
        // Try just using fopen to download the image.
        if( ini_get('allow_url_fopen') )
        {
            copy($_POST['thumb-url-upload'], $loc);
            $thumbUploaded = true;

        }
        else

        // If fopen doesn't work, try cURL.
        if( function_exists('curl_init') )
        {
            $ch = curl_init($_POST['thumb-url-upload']);
            $fp = fopen($loc, "wb");

            $options = array(CURLOPT_FILE => $fp,
                CURLOPT_HEADER => 0,
                CURLOPT_FOLLOWLOCATION => 1,
                CURLOPT_TIMEOUT => 60);
            curl_setopt_array($ch, $options);

            curl_exec($ch);
            curl_close($ch);

            fclose($fp);
            $thumbUploaded = true;
        }
    }
    else

    // Attempt to move the uploaded thumbnail to the thumbnail directory.
    if ( !empty($_FILES['thumbnail']['tmp_name']) && move_uploaded_file($_FILES['thumbnail']['tmp_name'], $loc) )
        $thumbUploaded = true;

    if ( $thumbUploaded )
    {
        if ( !update_post_meta($postID, 'custom_thumbnail', $thumbFileName) )
            add_post_meta($postID, 'custom_thumbnail', $thumbFileName);
    }

}
}