Task Timer/Stopwatch: PHP, MySQL, jQuery, AJAX

I need code developed for a task or project timer/stopwatch. Users should click a "Start" button which will automatically start a timeclock (jquery, ajax, etc.) which can be seen ticking up (00:00:01). There will be a stop button, as well, which will reset the clock and insert the record into the database. The stopwatch should continue if the page is refreshed. This will likely require usage of cookies, PHP session variables, or database entries. For example, once I start the timer, it should it should continue automatically until stopped, even if I refresh the page or navigate to another page within the application (PHP Session). The Stop (or Finish) button should use AJAX or jQuery to insert responses into the following MySQL fields: timer_id (auto), user_id, start_time, end_time, total_hours, status The timeclock will be visible in the header template section of a multi-page application. For example, if I start the timer on Page 1, and navigate to Page 2, the timer should continue where I left off and be visible on Page 2. There will be multiple users to the application at a time, so session variables may be required. Please let me know if you have any questions.