//preload 

var img1 = new Image();
img1.src = "../img/btn_home_over.gif";

var img2 = new Image();
img3.src = "../img/btn_drpena_over.gif";


var img3 = new Image();
img2.src = "../img/btn_services_over.gif";

var img4 = new Image();
img3.src = "../img/btn_treatments_over.gif";

var img5 = new Image();
img4.src = "../img/btn_forms_over.gif";

var img6 = new Image();
img5.src = "../img/btn_nutrition_over.gif";

var img7 = new Image();
img8.src = "../img/btn_healthtips_over.gif";

var img8 = new Image();
img7.src = "../img/btn_contact_over.gif";


//over
function over(img_name){
   document[img_name].src = "img/btn_" + img_name + "_over.gif";
}


function out(img_name){
   document[img_name].src = "img/btn_" + img_name + "_off.gif";
}