If I do something like
var url = "dynamicprice.php";
httpObject.open("GET", url, true);
everything works, but if I try to pass variables
var url = "dynamicprice.php?package=" + document.getElementById('package').value + "&markup=" + document.getElementById('markup').checked;
httpObject.open("GET", url, true);
I get no answer from dynamicprice.
What do I have to change?