<!DOCTYPE html>
<html>
<head>
<title>Title of the Document</title>
<script src="https://code.jquery.com/jquery-3.5.0.min.js"></script>
</head>
<body>
<input id="checkbox1" type="checkbox" name="one" value="1">
<input id="checkbox2" type="checkbox" name="two" value="2">
<input id="checkbox3" type="checkbox" name="thr" value="3">
<script>
$(document).ready(function() {
$('input[type="checkbox"]').click(function() {
if($(this).is(":checked")) {
alert("Checkbox is checked.");
}
else if($(this).is(":not(:checked)")) {
alert("Checkbox is unchecked.");
}
});
});
</script>
</body>
</html>