```js
function palindrome(str) {
    if (str == str.split('').reverse().join('')) {
        return true;
    } else {
        return false;
    }
}

console.log(palindrome('121'));
console.log(palindrome('racecar'));
console.log(palindrome('yourname'));
```

To find the plaindrome we're comparing the string input to the reverse version of the string. 

If both of the match, then the string is a plaindrome. 

We are reversing the contents of the string using built-in JavaScript methods of String and Array. 

Program to Check Whether a Number is Palindrome or Not.If the number is palindrome print true else print false.
i/p 121
o/p true 

JavaScript code please

1 Answer