<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<!------ Include the above in your HEAD tag ---------->
<!DOCTYPE html>
<html>
<body>
<input type="text" id="txt">
<button onclick="chk()">Check</button>
<p id="demo"></p>
<script>
function chk(){
var sm=document.getElementById('txt').value
var lk=sm.split("")
var io=""
for (var i=lk.length-1;i>=0;i--){
io+=lk[i]
}
if(io==sm){
alert("it is an palindrome")
}
else{
alert("it is not an palindrome")
}
document.getElementById('demo').innerHTML=io
}
</script>
</body>
</html>
