JS Caps Lock Detect

Detects Caps Lock on password field input and toggles warning with the caps lock keydown event

HTML

<input type="text" id="pwd">
<p id="caps"></p>

CSS

p {
    color: crimson;
}

JavaScript

$(function() {
	$('#pwd').on('keypress', shiftDetect);
	$(window).on('keydown', capsDetect);
});

var isDetected = false;
var capsOn = false;
	
function shiftDetect(event) {
	var caps = $('#caps');
	var which = event.keyCode;
	var shift = event.shiftKey;
	var targ = event.target;
	if ((which >= 65 && which <= 90 && !shift) || (which >= 97 && which <= 122 && shift)) {
		caps.html('CAPS LOCK IS ON');
		isDetected = true;
		capsOn = true;
	} else if((which >= 65 && which <= 90 && shift) || (which >= 97 && which <= 122 && !shift)){
		caps.html('');
	}
}
	
function capsDetect(event) {
	if(event.keyCode === 20 && isDetected) {
		capsOn = (capsOn)? false:true;
		if(capsOn) {
			$('#caps').html('CAPS LOCK IS ON');
		} else {
			$('#caps').html('');
		}
	}
}