MatchBox.js

matchbox.jquery.js

 (function ($, undefined) {
     $.fn.matchBox = function () {
     	var Boxes = this,
     	tallest = 0,
					 height;
			 Boxes.each(function(i){
				 height = $(this).height();
				 if(height > tallest){
					 tallest = height;
				 }
			 });
			 Boxes.height(tallest);
     }
 })(jQuery);

matchbox.js

function matchBox(elements){
  var Boxes = elements,
  tallest = 0,
  height;
  
  for(var i = 0, x = boxes.length; i < x; i++){
    
  }
			 Boxes.each(function(i){
				 height = $(this).height();
				 if(height > tallest){
					 tallest = height;
				 }
			 });
			 Boxes.height(tallest);
     }
}

matchBox(document.getElementsByClassName('js-matchbox'));