Use JS and ASP.NET C# to play sound and emails when a remote web page or control is modified

The code needs to check if a specific web page and/or button control has been modified. If its last modified date has changed since the last recorded value then it does 2 types of alerts. Play a sound, Send an Email to five recipients. The sound repeats until a button click on the page. The email sends 3 times over 30 minutes. The check of last modified occurs every 60 seconds. The check for the change of the button control can be done if required by identifying a change in the css class html. Delivery on this simple task today is preferred. Basic code and project supplied.