function createCookie(name, value, days)
{
    if (days) {
        var date = new Date();
        date.setTime(date.getTime()+(days*24*60*60*1000));
        var expires = "; expires="+date.toGMTString();
    }
    else var expires = "";
    document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name)
{
    var ca = document.cookie.split(';');
    var nameEQ = name + "=";
    for(var i=0; i < ca.length; i++) {
        var c = ca[i];
        while (c.charAt(0)==' ') c = c.substring(1, c.length); //delete spaces
        if (c.indexOf(nameEQ) == 0) {
            return c.substring(nameEQ.length, c.length);
        }
    }
    return null;
}

function eraseCookie(id)
{
    var name = 'product-'+id;
    createCookie(name, "", -1);
}

function recalculate(id, value)
{
    addToBag(id, value);
    window.location.href = window.location.href;
}

function addToBag(id, value)
{
    var name = 'product-'+id;

    createCookie(name,value,1);
}

function removeFromBag(id)
{
    eraseCookie(id);
}