hola necesito ayudaa

hola mira tengo estos codigos y quiero realizar la suma pero de todo esto pero error que tengo que cuando se uma y se escoge algun producto me sale decimales enormes ayudaaa
<script type="text/javascript">
function updateTotal(){
var basePrice=0;
var optionsPrice=0;

function checkShirt(){
if(document.getElementById('dominio1').checked){
optionsPrice += 9.9;
document.getElementById('subDom').innerHTML = 9.9+"0";
}

if(document.getElementById('dominio2').checked){
optionsPrice += 39.9;
document.getElementById('subDom').innerHTML = 39.9+"0";
}
if(document.getElementById('dominio3').checked){
optionsPrice += 59.9;
document.getElementById('subDom').innerHTML = 59.9+"0";
}
if(document.getElementById('dominio4').checked){
optionsPrice += 39.9;
document.getElementById('subDom').innerHTML = 39.9+"0";
}
if(document.getElementById('dominio5').checked){
optionsPrice += 59.9;
document.getElementById('subDom').innerHTML = 59.9+"0";
}
if(document.getElementById('dominio6').checked){
optionsPrice += 149.9;
document.getElementById('subDom').innerHTML = 149.9+"0";
}
}

function PreEmail(){
if (document.getElementById('email1').checked) {
optionsPrice += 6.9;
document.getElementById('subEmail').innerHTML = 6.9;+"0";
}
if (document.getElementById('email2').checked) {
optionsPrice += 9.9;
document.getElementById('subEmail').innerHTML = 9.9+"0";
}
if (document.getElementById('email3').checked) {
optionsPrice += 19.9;
document.getElementById('subEmail').innerHTML = 19.9+"0";
}

if (document.getElementById('email4').checked) {
optionsPrice += 189.9;
document.getElementById('subEmail').innerHTML = 189.9+"0";
}


}

function Hosting(){
if (document.getElementById('hosting1').checked) {
optionsPrice += 0;
document.getElementById('subHosting').innerHTML = 0+"0.0";
}
if (document.getElementById('hosting2').checked) {
optionsPrice += 9.9;
document.getElementById('subHosting').innerHTML = 9.9+"0";
}
if (document.getElementById('hosting3').checked) {
optionsPrice += 14.9;
document.getElementById('subHosting').innerHTML = 14.9+"0";
}

if (document.getElementById('hosting4').checked) {
optionsPrice += 29.9;
document.getElementById('subHosting').innerHTML = 29.9+"0";
}


}


function Template(){
if (document.getElementById('template1').checked) {
optionsPrice += 42.9;
document.getElementById('subTemplate').innerHTML = 42.9+"0";
}
if (document.getElementById('template2').checked) {
optionsPrice += 159.9;
document.getElementById('subTemplate').innerHTML = 159.9+"0";
}
if (document.getElementById('template3').checked) {
optionsPrice += 199.9;
document.getElementById('subTemplate').innerHTML = 199.9+"0";
}




}

function Delivery(){
if (document.getElementById('delivery1').checked) {
optionsPrice += 39.9;
document.getElementById('subDelivery').innerHTML = 39.9+"0";
}
if (document.getElementById('delivery2').checked) {
optionsPrice += 69.9;
document.getElementById('subDelivery').innerHTML = 69.9+"0";
}
if (document.getElementById('delivery3').checked) {
optionsPrice += 99.9;
document.getElementById('subDelivery').innerHTML = 99.9+"0";
}




}

movido a javascript

Es un problema del punto flotante amigo. Cada procesador lo maneja diferente, puedes utilizar algo como:

Código Javascript :

var result = Math.round(original*100)/100;

o el metodo tofixed info aquí:

http://www.pageresource.com/jscript/j_a_03.htm