gistfile1.js

var longestPalindrome = function (string) {
  // Your code here
  // Sliding window problem. 
  // If string is palindrom, return string
  // else check if substring of length stringLength-n is palindrome.
  // As soon as you get a palindrome you've found the longest palindrome
  // since you're shrinking the window and you want the longest one.
  var stringLength = string.length
  var n = 0;
  while( n < stringLength){
  	for( var i = 0; i < =n; i++ ){
  		if( isPalandrome( string.substring(i, stringLength-n+i) ) ){
  			return string.substring(i, stringLength-n+i);
  		}
  	}
  	n++;
  }
  return false;

}

var isPalandrome = function(string){
	// Code here.
	// Check if the first letter is the same as the last.
		//decriment and work your way in. 2nd same as 2nd to last etc
		//if ever this is not true. We return false
		//We only have to do this for half the string. :D
		var l = string.length
		for(var i = 0; i < l/2; i++){
			if( string.charAt(i) !== string.charAt(l-i-1) ) return false;
		}
		return true;
}