Adding html in wordpress plugin

I am writing my first wordpress plugin. It's supposed to send a message on plugin page whenever user saves/edits pages. The problem is I can't quite get it to print the messages.

Here is my code:

<?php

    /*
    Plugin Name: Monitor
    Plugin URI:
    Description: Test plugin monitoring user activities
    Author: 
    Version: 1.0
    Author URI: 
    */


if (!function_exists('p_update')) {  
    function p_update( $post_id ) {
        $post_title = get_the_title( $post_id );
        $post_url = get_permalink( $post_id );
        $message = "Changed: " . $post_title . "Link: " . $post_url ;
        echo "<p>test1</p>"
    }
}

if (!function_exists('p_publish')) {
    function p_publish( $post_id ){
        $post_title = get_the_title( $post_id );
        $post_url = get_permalink( $post_id );
        $message = "abc";
        echo "<p>test2</p>"
    }
}

if (!function_exists('plugin_menu')) {
    function plugin_menu() {
        add_menu_page( 'Monitor', 'Monitor', 'manage_options', __FILE__, 'plugin_options');
    }
}

if (!function_exists('plugin_options')) {
    function plugin_options() {
        if ( !current_user_can( 'manage_options' ) )  {
            wp_die( __( 'You do not have sufficient permissions to access this page.' ) );
        }
    echo '<div class="wrap">';
    echo '<p>test</p>';
    echo '</div>';
    }
}

add_action( 'admin_menu', 'plugin_menu' );
add_action('save_post', p_update);
add_action('publish_post', p_publish);

?>

The plugin_menu function displays html properly, but other functions can't do that. What am I doing wrong? I'm sure there is some easy way of doing that but no tutorial I've seen adresses this problem.

Thank you in advance for your help.

via Chebli Mohamed