function updateInventory( form, productId, variantOptionId )
{
	var inventoryId = "quantity";
	
	if ( typeof( variantOptionId ) != "undefined" )
		inventoryId += "_" + variantOptionId;
	else
		inventoryId += "_holder";

	$(inventoryId).innerHTML = "";
	var productOptions = new Array();
	
	Form.getElements(form).each( function(el){
		if ( el.name.startsWith("variants[") )
		{
			data = el.name.split("[");
			var variantId = parseInt(data[1]);
			productOptions.push({variantId:variantId, optionId:el.getValue()});
		}
	});
	
	var productOptionsData = "";
	
	productOptions = productOptions.sortBy(function(el){ return el.variantId });
	productOptions.each( function(el){
		productOptionsData += el.optionId + ";";
	});
	
	new Ajax.Updater( inventoryId, "quickCart/actions.php", { method: "post", parameters: { action: "getInventory", productId: productId, options: productOptionsData } } );
}