<!DOCTYPE html>
<html lang="en-US">
<body onkeydown="myFunction()">
<p>Select this text and press shift and do it again.</p>
<script>
document.designMode = "on";
function myFunction(){
if(event.keyCode == 16){
var state = document.queryCommandState("bold");
if(state)
alert("Bold formatting will be removed");
else
alert("Bold formatting will be added");
document.execCommand('bold');
}
}
</script> </body>
</html>