function changeAmount(item_id) {
	var total = $("#ppu_" + item_id).val() * parseInt($("#amount_" + item_id).val());
	if (!isNaN(total)) {
		$("#totalprice_" + item_id).html(getEuroString(total));
	} else {
		$("#totalprice_" + item_id).html(getEuroString(0));
	}
	computeTotal();
}

function computeTotal() {
	var total = 0;
	var nrflessen = 0;
	$('.ppu_item').each(function(i) {
		nrflessen += parseInt($("#amount_" + ($(this).attr('id')).replace('ppu_', '')).val());
		total += $(this).val() * parseInt($("#amount_" + ($(this).attr('id')).replace('ppu_', '')).val());
	});
	total += getTransport(nrflessen);
	if (!isNaN(total)) {
		$("#totalprice").html(getEuroString(total));
	} else {
		$("#totalprice").html(getEuroString(0));
	}
}

function getTransport(nrflessen) {
	$('.transport_1').hide();
	$('.transport_2').hide();
	$('.transport_3').hide();
	$('.transport_4').hide();
	if (nrflessen > 11) {
		$('.transport_4').show();
		return parseFloat($('#transport_4').val());
	} else if (nrflessen > 5) {
		$('.transport_3').show();
		return parseFloat($('#transport_3').val());
	} else if (nrflessen > 1) {
		$('.transport_2').show();
		return parseFloat($('#transport_2').val());
	} else {
		$('.transport_1').show();
		return parseFloat($('#transport_1').val());
	}
}

function getEuroString(s) {
		s = Math.round(s*100)/100;		// afronden tot op 2 cijfers na de komma
		var a = (''+s).replace(".",",") + getPostFix(s);
		return a;
	}

function getPostFix(price) {
	var postfix = '';
	if ((Math.floor(price)*100 == Math.round(price*100)) || price==0) {		// always 2 after comma
		postfix = ',00';
	} else if ((Math.floor(price*10)*10 == Math.round(price*100))) {
		postfix = '0';
	}
	return postfix;
}