this is a function of the way forms work.
if you set your form to use the GET method, the form data will be passed through the query string
if you set your form to use the POST method, there is no querystring
your form is using the post method. there is no querstring created using this form method.
the only way to get the form information is by using the $_POST array from my example in the previous reply.
you are asking me how to get information that does not exist because of the method that the form uses.
If you want the information to passed through the querystring, then you need to change the forms method from POST to GET.