var slideImg = new Array();
slideImg[0] = new Image();
slideImg[1] = new Image();

slideImg[0].src = "/display/image/mainImage_medical.jpg";
slideImg[1].src = "/display/image/mainImage_touch.jpg";

var i = 0;
function slidePics() {
   if (i == slideImg.length-1) {
	   i = 0;
   } else {
	   i++;
   }
   document.getElementById("slide").src = slideImg[i].src;
}