This is an INsensitive case

Hey guys!
Can I make this Array case insensitive?


Array.prototype.contains = function(searchValue) {
 var i = this.length;
 while (i--) {
  if (this* == searchValue) {
   return true;
  }
 }
 return false;
};

If so, how do I go about it? Any clues?

Thanks for the attention and any help!:beer: