<!DOCTYPE html> <html> <body> <h1>The input popovertargetaction Attribute</h1> <h1 popover id="myheader">Hello</h1> <input type="button" popovertarget="myheader" popovertargetaction="show" value="Show"> <input type="button" popovertarget="myheader" popovertargetaction="hide" value="Hide"> <input type="button" popovertarget="myheader" popovertargetaction="toggle" value="Toggle"> <p>Click the buttons to show/hide the popover element.</p> </body> </html>