function doChange(i){
	changeItems(i);
}
function changeItems(i){
   switch(i){
   case 1:
	   document.getElementById("product").style.display="block";
	   document.getElementById("product1").style.display="none";
	   document.getElementById("product2").style.display="none";
	   document.getElementById("product3").style.display="none";
	   break;
   case 2:
	   document.getElementById("product").style.display="none";
	   document.getElementById("product1").style.display="block";
	   document.getElementById("product2").style.display="none";
	   document.getElementById("product3").style.display="none";
	   break;
   case 3:
	   document.getElementById("product").style.display="none";
	   document.getElementById("product1").style.display="none";
	   document.getElementById("product2").style.display="block";
	   document.getElementById("product3").style.display="none";
	   break;
   case 4:
	   document.getElementById("product").style.display="none";
	   document.getElementById("product1").style.display="none";
	   document.getElementById("product2").style.display="none";
	   document.getElementById("product3").style.display="block";
	   break;
	}
  
}