title: Alert to warn user to click button after a set time
body: <p>What I want to do is (in JavaScript&amp;html): </p>
  
  <p>If after 5 minute of opening the page, the user haven't clicked a particular button on the page, I want the system to display an alert to remind user to click the button. And if the user still haven't clicked the button after the alert, the alert will display again after another 5 minute. But once the user clicked the button, the alert will not show again. </p>
  
  <p>Any help will be appreciated! </p>