var CharacterCounter = function(source, target) {
	var maxChars = source.attr('maxlength');

	if(maxChars == null) {
		maxChars = target.text().match(/\d+/);
	}
	
	var specialChars = [8,33,34,35,36,37,38,39,40,46];
	
	var updateCount = function(e) {
	  var charsLeft = maxChars - source.val().length;
	  target.text("Characters left: " + charsLeft);
	  return charsLeft > 0 || (jQuery.inArray(e.which, specialChars) != -1);
	};
	
	source.keyup(updateCount);
	source.keydown(updateCount);
};