It sounds like the problem you're having is loss of some essential parameters to your page when posting. In ASP there are two primary methods of passing parameters, in the url string via GET or from a form POST. The former passes you values in the QueryString dictionary while the latter gives them to you in the Form dictionary. Fortunately for you it is possible to accept a parameter that exists in EITHER dictionary by looking to Request object:
Request["a"]
will find a regardless of being in Request.QueryString["a"]
or Request.Form["a"]
.
This will help you in your current dilemma because you can simply write your querystring parameters to your Form on initial load of the page as <input type="hidden"
fields. On subsequent posts your Request["a"]
search for your parameters will find them regardless of being passed in the URL (on initial load) or via post on subsequent calls.