var http_request = false;
function makePOSTRequest(url, parameters) {

   http_request = false;
   if (window.XMLHttpRequest) {
      http_request = new XMLHttpRequest();
      if (http_request.overrideMimeType) {
         http_request.overrideMimeType('text/html');
      }
   } else if (window.ActiveXObject) {
      try {
         http_request = new ActiveXObject("Msxml2.XMLHTTP");
      } catch (e) {
         try {
            http_request = new ActiveXObject("Microsoft.XMLHTTP");
         } catch (e) {}
      }
   }
   if (!http_request) {
      alert('Cannot create XMLHTTP instance');
      return false;
   }
   if(url=='ajax.shop_cat.php') {
	   http_request.onreadystatechange = alertContents;
   } else if(url=='ajax.shop_discount.php') {
	   http_request.onreadystatechange = alertContents2;
   }
   
   http_request.open('POST', url, true);
   http_request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
   http_request.setRequestHeader("Content-length", parameters.length);
   http_request.setRequestHeader("Connection", "close");
   http_request.send(parameters);
}

function alertContents() {

   if (http_request.readyState == 4) {
      if (http_request.status == 200) {
         result = http_request.responseText;
         document.getElementById('response').innerHTML = result;    
      } else {
         alert('There was a problem with the request.');
      }
   }
}

function alertContents2() {

	   if (http_request.readyState == 4) {
	      if (http_request.status == 200) {
	         result = http_request.responseText;
	         document.getElementById('response2').innerHTML = result;    
	      } else {
	         alert('There was a problem with the request.');
	      }
	   }
}

function shop_cat_get(obj) {
   var poststr = "prod_id=" + escape(encodeURI( document.getElementById("prod_id").value ));
   makePOSTRequest('ajax.tilaus.php', poststr);
}

function shop_discount(obj) {
	   var poststr = "discount=" + escape(encodeURI( document.getElementById("discount").value ))+
	   				 "&orig=" + escape(encodeURI( document.getElementById("price").value ));
	   makePOSTRequest('ajax.shop_discount.php', poststr);
}