$(document).ready(function(){

  $(function() {
    $(".mouseover").hover(function() {
          $(this).attr("src", $(this).attr("src").split(".").join("-over."));  // adds -hover to the name of the image
    }, function() {
          $(this).stop(true,false); // prevents the creation of stacked actions
          $(this).attr("src", $(this).attr("src").split("-over.").join("."));  // removes -hover from the name of the image
    });
  });


});