var req;
var g_id=0;
function loadXMLDoc(url) {
    if (window.XMLHttpRequest) {
        req = new XMLHttpRequest();
        req.onreadystatechange = processReqChange;
        req.open("GET", url, true);
        req.send(null);
    } else if (window.ActiveXObject) {
        req = new ActiveXObject("Microsoft.XMLHTTP");
        if (req) {
            req.onreadystatechange = processReqChange;
            req.open("GET", url, true);
            req.send();
        }
    }
}
function processReqChange() 
{
    if (req.readyState == 4) {
        if (req.status == 200) {
      response = req.responseText;
      addToCart('', '', response);
        } else {
            alert("There was a problem retrieving the XML data:\n" + req.statusText);
        }
    }
}
function addToCart(id, quant, response)
{
  if (response == 'exists'){
  	  alert('Вы уже заказали этот товар.\r\nИзменить количество можно на странице \"Ваш заказ\".');
  }
  else if (response == 'zero'){
  	  alert('Количество товара должно быть больше 0.');
  }
  else if (response != ''){ 
    // Response mode
    response = response.split('+-+');
	alert('Товар добавлен в заказ');
  }else{
    // Input mode
    url  = '/inc/cart_add.php?id='+id+'&quant='+quant;
    loadXMLDoc(url);
  }
}

function loadXMLDoc1(url,id) {
	g_id=id;
    if (window.XMLHttpRequest) {
        req = new XMLHttpRequest();
        req.onreadystatechange = processReqChange1;
        req.open("GET", url, true);
        req.send(null);
    } else if (window.ActiveXObject) {
        req = new ActiveXObject("Microsoft.XMLHTTP");
        if (req) {
            req.onreadystatechange = processReqChange1;
            req.open("GET", url, true);
            req.send();
        }
    }
}
function processReqChange1() 
{
    if (req.readyState == 4)
    {
        if (req.status == 200)
        {
	      	response = req.responseText;
			renewCart('', '', response);
        }
        else
        {
            alert("There was a problem retrieving the XML data:\n" + req.statusText);
        }
    }
}
function renewCart(id, quant, response)
{
  if (response == 'exists'){
  	  alert('Данный товар уже присутствует в Вашей корзине.\r\nИзменить количество можно на странице заказа.');
  }
  else if (response == 'zero'){
  	  alert('Количество товара должно быть больше 0.');
  }
  else if (response != ''){ 
    // Response mode
    response = response.split('+-+');
    cost = response[0];
    goods_no = response[1];
    totalusd = response[2];
    totalrur = response[3];
    span3 = document.getElementById('cost_'+g_id);
    span4 = document.getElementById('cost_total_usd');
    span5 = document.getElementById('cost_total_rur');
	span3.innerHTML=cost;
	span4.innerHTML=totalusd+' $';
	span5.innerHTML=totalrur+' р.';
  }else{
    // Input mode
    url  = '/inc/cart_modify.php?id='+id+'&quant='+quant;
    loadXMLDoc1(url,id);
  }
}