var d = document;

function get_xmlhttp() {
	var xmlhttp=false;

	/*@cc_on @*/
	/*@if (@_jscript_version >= 5)
	try {
		xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
	} catch (e) {
		try {
			xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
		} catch (E) {
			xmlhttp = false;
		}
	}
	@end @*/
	if (!xmlhttp && typeof XMLHttpRequest!='undefined') {
		xmlhttp = new XMLHttpRequest();
	}
	
	return xmlhttp;
}

function insert_into_cart(prod_id, tmp_user) {
	xmlhttp = get_xmlhttp();
	error = false;
	
	try {
		elem_amount = d.getElementById("p_amount_" + prod_id);
		amount = check_if_valid(elem_amount.value); 
		if(amount == false)
			error = true;

		elem = d.getElementById("p_price_" + prod_id);
		price = check_if_valid(elem.innerHTML); 

		elem = d.getElementById("p_discount_" + prod_id);
		discount = check_if_valid(elem.innerHTML); 


		ud_elem = d.getElementById("user_discount");
		user_discounts = check_if_valid(ud_elem.innerHTML); 

		md_elem = d.getElementById("money_discount");
		money_discounts = check_if_valid(md_elem.innerHTML); 

		tc_elem = d.getElementById("total_cost");
		total_costs = check_if_valid(tc_elem.innerHTML); 

		dc_elem = d.getElementById("discounted_cost");
		discounted_costs = check_if_valid(dc_elem.innerHTML);

		if(error) {
			alert("Netinkamas formatas!");
			elem_amount.value = 0;
			return;
		}
	}
	catch(exp) {
		alert("Prekes kaina ir kiekis turi buti skaiciai!");
		return;
	}
	
	xmlhttp.onreadystatechange = function() {
		if( xmlhttp.readyState == 1 )
	   {
	   }
	   if( xmlhttp.readyState == 2 )
	   {
	   }
	   if( xmlhttp.readyState == 3 )
	   {
	   }
	   if( xmlhttp.readyState == 4 ) {
	   	arr = eval(xmlhttp.responseText);
			md = eval("arr[0] - arr[1]");
			tc_elem.innerHTML = money_format(arr[0]);
			dc_elem.innerHTML = money_format(arr[1]);
			md_elem.innerHTML = money_format(md);			
			d.getElementById("p_amount_" + prod_id).value = 0;
			d.getElementById("inside_cart").className = "full";
			d.getElementById("small_cart_" + prod_id).className = "small_full";
	   }
   }
	
    if(tmp_user){
        url = "cart/bg_insert/?id=" + prod_id + "&amount=" + amount + "&tmp_user=1";
    }else{
        url = "cart/bg_insert/?id=" + prod_id + "&amount=" + amount;    
    }
	
	send_req(xmlhttp, url);

	return false;
}
// number as string
function check_if_valid(num) {
	if(!is_numeric(num)) {
		return false;
	}
	else {
		return parseFloat(num);
	}
}

function send_req(xmlhttp, url) {
	xmlhttp.open( "GET", url, true );
	if(navigator.userAgent.indexOf('ie') == -1)
		xmlhttp.send( null );
	else
		xmlhttp.send();
}