if (document.images) {
  imageAon = new Image();
  imageAon.src = "images/power-gen-ownersON.gif";

  imageAoff = new Image();
  imageAoff.src = "images/power-gen-owners.gif";
  
  imageBon = new Image();
  imageBon.src = "images/retail-electricityON.gif";

  imageBoff = new Image();
  imageBoff.src = "images/retail-electricity.gif";
  
  imageCon = new Image();
  imageCon.src = "images/large-consumersON.gif";

  imageCoff = new Image();
  imageCoff.src = "images/large-consumers.gif";
  
  imageDon = new Image();
  imageDon.src = "images/renewable-powerON.gif";

  imageDoff = new Image();
  imageDoff.src = "images/renewable-power.gif";
  
  imageEon = new Image();
  imageEon.src = "images/fossil-fuelON.gif";

  imageEoff = new Image();
  imageEoff.src = "images/fossil-fuel.gif";
  
  imageFon = new Image();
  imageFon.src = "images/financial-entitiesON.gif";

  imageFoff = new Image();
  imageFoff.src = "images/financial-entities.gif";
  
}


function changeImages() {
  if (document.images) {
    for (var i=0; i<changeImages.arguments.length; i+=2) {
      document[changeImages.arguments[i]].src = eval(changeImages.arguments[i+1] + ".src");
    }
  }
}