Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.
show event is fired when a
contextmenu event was fired on/bubbled to an element that has a
<menu type="context" id="test">
<menuitem label="alert" onclick="alert('the alert label has been clicked')" />
alert("the context menu will be displayed");
This event is not on any standards track.