Forming a URL with a querystring

http://www.coupons.com/ajax/init/?

This URL returns json data, that I call from Excel using VBA. It returns the POD data info perfect, but I am trying to expand the URL to also list the json data for the following.
var pid = GetQueryStringValue ('pid')
var nid = GetQueryStringValue ('nid')
var zid = GetQueryStringValue ('zid')

This is the type of URL I want to form, but I need to know the parameters for the "pid" and "zid" to form URLs other than the one shown below.
http://www.coupons.com/ajax/init?pid...id=iq37&nid=10

Thank you very much for any insight someone can provide.

Thank you for the response. I know the 3 parameters from the home website
http://www.coupons.com/coupons/pid=1...d=10&zid=iq37/

I also know that various websites that use coupons.com as an affiliate have their own parameters assigned.
For instance this URL returns the json for Walmart's.
http://www.coupons.com/ajax/init?pid...id=10&zid=vz89

I am trying to figure out how I can return a query that gives me a complete listing of the 3 parameters.
The most important parameter is the "zid", which on some older html is also referred to as "campaign".
If I had a list of the 3 parameters, I can query the different URLs to make a complete list of all coupons available.

I am fairly certain this javascript contains the info needed to acquire the data I am looking for, but I have not been able to figure out how to create the URL
to "GetQueryStringValue" for the zid value.
http://cdn.cpnscdn.com/nv.web/combo/...4d893911fcb.js

I apologize if my terminology isn't very clear, I sort of just try and teach myself as I go along.