// javascript originally from www.happycog.com
// generic preload 

function newImage(arg) {
if (document.images) {
rslt = new Image();
rslt.src = arg;
return rslt;
}
}

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

var preloadFlag = false;
function preloadImages() {
if (document.images) {

home_over = newImage("/images/home_over.gif");
dentistry_over = newImage("/images/dentistry_over.gif");
orthodontics_over = newImage("/images/orthodontics_over.gif");
the_jaw_joint_over = newImage("/images/the_jaw_joint_over.gif");
snoring_over = newImage("/images/snoring_over.gif");
about_over = newImage("/images/about_over.gif");
preloadFlag = true;
}
}

// toggle visibility 

function toggle( targetId ){
  if (document.getElementById){
  		target = document.getElementById( targetId );
  			if (target.style.display == "none"){
  				target.style.display = "";
  			} else {
  				target.style.display = "none";
  			}
  	}
}