Using $var across pages and in the document

Hello everyone,

This is a script I wrote a while back which I’m experimenting with. The plan is to make a single web page in the admin panel which has these fields:

Ip:
Port:
Width:
Height:

I then want these fields to go to various plugins one of which is below:

However I believe I am doing something wrong?

Thanks

<?php
/*
Plugin Name: Server Status
Plugin URI: https://minepress.co.uk
Description: Server Status Plugin
Author: Bradly spicer
Version: 1.0.0
Author URI: https://minepress.co.uk
*/

class ServerStatus extends WP_Widget
{
  function ServerStatus()
  {
    $widget_ops = array('classname' => 'ServerStatus', 'description' => 'Displays Server Status' );
    $this->WP_Widget('ServerStatus', 'Server Status display', $widget_ops);
  }

  function form($instance)
  {
    $instance = wp_parse_args( (array) $instance, array( 'title' => '' ) );
    $title = $instance['title'];
    $ip= $instance['ip'];
    $port= $instance['port'];
?>
  <p><label for="<?php echo $this->get_field_id('title'); ?>">Title: <input class="widefat" id="<?php echo $this->get_field_id('title'); ?>" name="<?php echo $this->get_field_name('title'); ?>" type="text" value="<?php echo attribute_escape($title); ?>" /></label></p>
    <p><label for="<?php echo $this->get_field_id('port'); ?>">Ip: <input class="widefat" id="<?php echo $this->get_field_id('ip'); ?>" name="<?php echo $this->get_field_name('ip'); ?>" type="text" value="<?php echo attribute_escape($ip); ?>" /></label></p>
        <p><label for="<?php echo $this->get_field_id('port'); ?>">Port: <input class="widefat" id="<?php echo $this->get_field_id('port'); ?>" name="<?php echo $this->get_field_name('port'); ?>" type="text" value="<?php echo attribute_escape($port); ?>" /></label></p>
<?php
  }

  function update($new_instance, $old_instance)
  {
    $instance = $old_instance;
    $instance['title'] = $new_instance['title'];
    $instance['ip'] = $new_instance['ip'];
    $instance['port'] = $new_instance['port'];
    return $instance;
  }

  function widget($args, $instance)
  {
    extract($args, EXTR_SKIP);

    echo $before_widget;
    $title = empty($instance['title']) ? ' ' : apply_filters('widget_title', $instance['title']);
    $ip = empty($instance['ip']) ? ' ' : apply_filters('ip', $instance['ip']);
    $port = empty($instance['port']) ? ' ' : apply_filters('port', $instance['port']);

    if (!empty($title))
      echo $before_title . $title . $after_title;;

    // WIDGET CODE GOES HERE
?><div id="Server_status"><?php $online = @fsockopen("play.magicacraft.net", "25567", $errno, $errstr, 1);
if($online >= 1) {
echo 'Online!';
}
else {
echo 'Offline!';
}
?>
</div>

 <?php
    echo $after_widget;
  }

}
add_action( 'widgets_init', create_function('', 'return register_widget("ServerStatus");') );?>
<?php 

add_shortcode('MP-IPSHOW', 'MP_IPshow');
function MP_IPshow() {
$ip= $instance['ip'];
echo $ip . ':8123/';
/*end of shortcode */
}
add_shortcode('MP-IPSHOW', 'MP_IPshow');
?>