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.