Help! My Plugin Can’t Work, Can’t Read From Database

I’ve started to create a plugin that able users to automatically send their new post to Twitter and Del.icio.us.
I’ve create Admin page and Plugin code, plugin can be installed and configuration can be saved. But still this plugin can’t work.
Please help me review and fix the code. I will add your name to dontributor list if this plugin work and released.
Code for plugin

<?php
/*
Plugin Name: Autoposter
Plugin URI: http://blog.sendaljepit.net/
Description: This plugin will automatically feed your new post to Twitter, Tumblr and Del.icio.us. Please note that if you activate any other plugins that do the same action, you'll have double post.
Version: 1.0
Author: Bambang Catur
Author URI: http://blog.sendaljepit.net/
*/

/* Copyright 2009 Bambang Catur (email : broxenhearted@gmail.com)

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/

function autopost($post_ID) {
global $twitter_username, $twitter_password, $tumblr_email, $tumblr_password, $delicious_username, $delicious_password, $tags;
$post_title = stripslashes($_POST['post_title']);
$post_title = html_entity_decode($post_title);
$tumblr_text = html_entity_decode($_POST[content]);
$tumblr_text = strip_tags($tumblr_text);
$tumblr_text = nl2br($tumblr_text);
$tumblr_text = substr($tumblr_text, 0,200);
$permalink = get_permalink($post_ID);
$tumblr_text .= "Read more at the source: $post_title";
$tw_title = substr($post_title, 0,70);

// Tweeting
if($twitter_username && $twitter_password){
$message = "$tw_title $permalink";
$url = 'http://twitter.com/statuses/update.xml';
$curl_handle = curl_init();
curl_setopt($curl_handle, CURLOPT_URL, "$url");
curl_setopt($curl_handle, CURLOPT_CONNECTTIMEOUT, 2);
curl_setopt($curl_handle, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl_handle, CURLOPT_POST, 1);
curl_setopt($curl_handle, CURLOPT_POSTFIELDS, "status=$message");
curl_setopt($curl_handle, CURLOPT_USERPWD, "$twitter_username:$twitter_password");
$buffer = curl_exec($curl_handle);
curl_close($curl_handle);

// Please keep this promotional sections to keep this Plugin alive.
$ld = substr($post_ID, -1);
if($ld == 1 || $ld == 6 || $ld == 9){
$data = "Get free wordpress resources: http://blog.sendaljepit.net/";
$lines = explode("\n", $data);
shuffle($lines);
$message = str_replace("\n", "", $lines[0]);
$url = 'http://twitter.com/statuses/update.xml';
$curl_handle = curl_init();
curl_setopt($curl_handle, CURLOPT_URL, "$url");
curl_setopt($curl_handle, CURLOPT_CONNECTTIMEOUT, 2);
curl_setopt($curl_handle, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl_handle, CURLOPT_POST, 1);
curl_setopt($curl_handle, CURLOPT_POSTFIELDS, "status=$message");
curl_setopt($curl_handle, CURLOPT_USERPWD, "$twitter_username:$twitter_password");
$buffer = curl_exec($curl_handle);
curl_close($curl_handle);
}
// End of Tweeting
}

//Tumblr
if($tumblr_email && $tumblr_password){
$post_type = 'regular';
$request_data = http_build_query(
array(
'email' => $tumblr_email,
'password' => $tumblr_password,
'type' => $post_type,
'title' => $post_title,
'body' => $tumblr_text,
'generator' => 'Web'
)
);

$c = curl_init('http://www.tumblr.com/api/write');
curl_setopt($c, CURLOPT_POST, true);
curl_setopt($c, CURLOPT_POSTFIELDS, $request_data);
curl_setopt($c, CURLOPT_RETURNTRANSFER, true);
$result = curl_exec($c);
$status = curl_getinfo($c, CURLINFO_HTTP_CODE);
curl_close($c);

//delicious
$del_title = urlencode($post_title);
$del_desc = substr($tumblr_text, 0,80);
$del_desc = urlencode($del_desc);
$del_tags = urlencode($tags);
file_get_contents("https://$delicious_username:$delicious_password@api.del.icio.us/v1/posts/add?url=$permalink&description=$del_title&extended=$del_desc&tags=$del_tags&shared=yes");

}

return $post_ID;
}

add_action ( 'publish_post', 'autopost' );

function autoposter_admin() {
include('autoposter_admin.php');
}

function autoposter_admin_actions() {
add_options_page("Autoposter Configuration", "Autoposter Configuration", 1, "Autoposter Configuration", "autoposter_admin");
}

add_action('admin_menu', 'autoposter_admin_actions');

?>

Code for admin

<?php
if($_POST['autoposter_hidden'] == 'Y') {
//Form data sent
$twitter_username = $_POST['twitter_username'];
update_option('twitter_username', $twitter_username);

$twitter_password = $_POST['twitter_password'];
update_option('twitter_password', $twitter_password);

$tumblr_email = $_POST['tumblr_email'];
update_option('tumblr_email', $tumblr_email);

$tumblr_password = $_POST['tumblr_password'];
update_option('tumblr_password', $tumblr_password);

$delicious_username = $_POST['delicious_username'];
update_option('delicious_username', $delicious_username);

$delicious_password = $_POST['delicious_password'];
update_option('delicious_password', $delicious_password);

$tags = $_POST['tags'];
update_option('tags', $tags);
?>
<div class="updated"><p><?php _e('Configuration saved sucessfully.' ); ?></p></div>
<?php
} else {
//Normal page display
$twitter_username = get_option('twitter_username');
$twitter_password = get_option('twitter_password');
$tumblr_email = get_option('tumblr_email');
$tumblr_password = get_option('tumblr_password');
$delicious_username = get_option('delicious_username');
$delicious_password = get_option('delicious_password');
$tags = get_option('tags');
}

?>

<div class="wrap">
<?php echo "<h2>" . __( 'Autoposter Configuration', 'autoposter_trdom' ) . "</h2>"; ?>

<form name="autoposter_form" method="post" action="<?php echo str_replace( '%7E', '~', $_SERVER['REQUEST_URI']); ?>">
<input type="hidden" name="autoposter_hidden" value="Y">
<?php echo "<h4>" . __( 'Delicious Tweet Settings', 'autoposter_trdom' ) . "</h4>"; ?>
<p><?php _e("Twitter Username : " ); ?><input type="text" name="twitter_username" value="<?php echo $twitter_username; ?>" size="20"></p>
<p><?php _e("Twitter Password : " ); ?><input type="text" name="twitter_password" value="<?php echo $twitter_password; ?>" size="20"></p>
<p><?php _e("Tumblr E-mail Address: " ); ?><input type="text" name="tumblr_email" value="<?php echo $tumblr_email; ?>" size="20"></p>
<p><?php _e("Tumblr Password : " ); ?><input type="text" name="tumblr_password" value="<?php echo $tumblr_password; ?>" size="20"></p>
<p><?php _e("Del.icio.us Username : " ); ?><input type="text" name="delicious_username" value="<?php echo $delicious_username; ?>" size="20"></p>
<p><?php _e("Del.icio.us Password : " ); ?><input type="text" name="delicious_password" value="<?php echo $delicious_password; ?>" size="20"></p>
<hr />
<?php echo "<h4>" . __( 'Tag Setting For Del.icio.us', 'autoposter_trdom' ) . "</h4>"; ?>
<p><?php _e("Tags (separate by space): " ); ?><input type="text" name="tags" value="<?php echo $tags; ?>" size="20"><?php _e(" ex: computer blog hosting wordpress" ); ?></p>

<p class="submit">
<input type="submit" name="Submit" value="<?php _e('Update Options', 'autoposter_trdom' ) ?>" />
</p>

</form>
</div>