function changeItemCount(target, action)
{
	var target = target.parentNode.getElementsByTagName('input');
	var count = target[0].value;
	if(action == 'add')
	{
		count++;
	}
	else
	{
		if(count > 0)
		{
			count--;
		}
	}
	target[0].value = count;
	// recalculate total sum
	totalSumBasket();
	return false;	
}

function removeFromBasket(modelId, size)
{
	var elements = document.getElementsByName("row_"+modelId+"_"+size);
	for ( i=0; i<elements.length; i++ )
	{
		elements[i].style.display = "none";
	}
	countSizeInModel[ modelId ]--;
	if ( countSizeInModel[ modelId ] == 0 ) {
		row_els = document.getElementsByName("row_"+modelId);
		for ( i=0; i<row_els.length; i++ )
		{
			row_els[i].style.display = "none";
		}
	}

	document.forms['basket'].elements["count_"+modelId+"_"+size].value = 0;

	// recalculate total sum
	totalSumBasket();
}
function totalSumBasket() 
{
	els = document.forms['basket'].elements;
	totalSum = 0;
	for ( var i in els ) {
		elid = els[i].id;
		if (elid != undefined && elid!="" && elid.indexOf("price_") === 0) {
			suffix = els[i].id.substring(6);
			if ( els[i].style.display == "none" ) continue;
			price = els[i].value;
			count = document.forms['basket'].elements["count_"+suffix].value;
			sum = count*price;
			document.getElementById("res_price_"+suffix).innerHTML=sum;
			totalSum += sum;
		}
	}
	var totalSumEl = document.getElementById("total_sum");
	totalSumEl.innerHTML = totalSum;
}
function clearDefContent( element, def )
{
	if ( element.value == def ) 
		element.value = "";
}
function restoreDefContent( element, def )
{
	if ( element.value == "" ) 
		element.value = def;
}