Use the
oncopy
event of your document. This event is fired when the user copies content by pressing Ctrl-C, by using the context menu and choosing Copy, or when using the browser window menu and choosing edit/copy.
So all you need do is call your function in response to that event:
document.oncopy =$(function(){
$('#dsply').hide();
setTimeout(function(){
$('#dsply').fadeIn('slow');
},30000);
});
Read more about clipboard events, including cancelling them, accessing clipboard data etc at
https://www.w3.org/TR/clipboard-apis/#clipboard-event-copy[
^]