Check for Palindrome in JavaScript

Here is the code:

(function(){

'use strict';

var testStringOne = "Madam";

var testStringTwo = "testing";

var testNull = null;

var testUndefined;

console.log(checkIfPalindrome(testStringOne));

console.log(checkIfPalindrome(testStringTwo));

console.log(checkIfPalindrome(testNull));

console.log(checkIfPalindrome(testUndefined));

function checkIfPalindrome(testStringOne){

if(!testStringOne){

return false;

}

var testArrayOne = testStringOne.toLowerCase().split("");

testArrayOne.reverse();

if(testArrayOne.toString() == testStringOne.toLowerCase().split("").toString()){

return true;

}else{

return false;

}

}

})();