code: function(raw) {
  		if (typeof(raw) !== "string") $.error("String expected.");
  		var split = raw.split('x');
  		if (split.length !== 2) $.error("Should be two elements only.");
  
  		var list = [];
  		$.each(split, function() {
  			var digit = Number($.trim(this));
  			if (isNaN(digit)) $.error(this + " is not a digit.");
  			list.push(digit);
  		});
  
  		return list;
  	}
docs: Convert a string with two digits, separated by x, into an array with two
  values. Ie. "123x456" becomes [123,456]