У вашего броузера проблема в совместимости с HTML5
In this video you will learn to update data in mysql using jquery and ajax without refreshing page. you can download source code from the link below
http://developer-zone.000webhostapp.com/2017/09/update-data-using-jquery-ajax-php-and-mysql
Or download direct from here
https://developer-zone.000webhostapp.com/wp-content/uploads/2017/09/update_ajax_tutorial.zip