$(document).ready(function() {

  var preload1 = new Image();
  var preload2 = new Image();
  preload1.src = "psycho2.jpg";
  preload2.src = "heat2.jpg";

  var random = Math.ceil(Math.random()*2);
  var image = document.createElement("img");  
  random == 1 ? image.src = "psycho1.jpg" : image.src = "heat1.jpg";

  $("#gratuity").append(image);
  
  $(image).hover(
	 function() {
		random == 1 ? this.src = "psycho2.jpg" : this.src = "heat2.jpg";
	 },
	 function() {
		random == 1 ? this.src = "psycho1.jpg" : this.src = "heat1.jpg";
	}
  );

});