function _update_cart(id, v) {

    var cookie_name = "cookie1_pr=";

    var value = v ? v : (document.f["c"+id].checked ? document.f["q"+id].value : 0);

    var c1, cvalue, i2;
    var name = "p"+id+"%3D";
    var c = document.cookie;
    var i = c.indexOf(cookie_name);
    if (i == -1) {
        c1 = "";
    } else {
        i += cookie_name.length;         
        i2 = c.indexOf(";", i); 
        if (i2 == -1) c1 = c.substring(i, c.length);
        else c1 = c.substring(i, i2);
    } 

    if (c1.length) {
        i = c1.indexOf(name);
        if (i == -1) cvalue = c1+"%26"+name+value;
        else {
            i2 = c1.indexOf("%26", i);        
            cvalue = c1.substring(0, i+name.length) + value;
            if (i2 != -1) cvalue += c1.substring(i2, c1.length);
        }        
    } else {
       cvalue = name+value;        
    }

    document.cookie = cookie_name + cvalue; 
    location.reload();
}