Updated_post_meta in wordpress executing after removing the code

I am learning plugin development in wordpress.where in my plugin i used updated_post_meta function to test how it works.below is the function i used in my plugin

 function __construct()
   {

    if(is_admin()){
        add_action('init',array(&$this,'setup_tinymce_plugin'));
        add_action('updated_post_meta','save_post_apr');
    }

  }

function save_post_apr($post_id)
{

            echo '<script>alert("'.$post_id.'");</script>';
}

the function works perfectly but after checking i removed the code but it still showing the alert in edit post page or update post.i had removed the entire code belongs to the function but still the fucntion executes. if i change the theme i am not seeing the alert

via Chebli Mohamed