This has to do with a shopping cart system that I do not have complete control
of. The scenario is an executable using html templates which I can alter.
But I have no control of when or if the html pages are called.

When an item is ordered I create a Session variable for it:
<%
If InStr("<!Name>","Railroad") Then Session("rms") = 1
If InStr("<!Name>","Switching") Then Session("swadv") = 1
If InStr("<!Name>","Traffic") Then Session("tplan") = 1
If InStr("<!Name>","City") Then Session("city") = 1
%>
When it's deleted I set the variable to zero:
<%
If InStr("<!Name>","Railroad") Then Session("rms") = 1
If InStr("<!Name>","Switching") Then Session("swadv") = 1
If InStr("<!Name>","Traffic") Then Session("tplan") = 1
If InStr("<!Name>","City") Then Session("city") = 1
%>
But if it's never ordered then the Session variable just doesn't get created
at all, and therein lies the problem.
On the last page before I leave the server (and the Session) I put those
variables into a form:
<form method=post action="http://w.../Download.asp">
<% cntr = 0
cntr = Session("rms") %>
<input type=hidden name="rms" value=<%= cntr %>>
<% cntr = Session("swadv") %>
<input type=hidden name="swadv" value=<%= cntr %>>
<% cntr = Session("tplan") %>
<input type=hidden name="tplan" value=<%= cntr %>>
<% cntr = Session("city") %>
<input type=hidden name="city" value=<%= cntr %>>
<input type=submit value=" Click to continue ">
</form>
Then in the target (Download.asp) file I use the form variables:
<%
If Request.Form("rms") > 0 Then
Response.Write("<a href=%22http://myurl/rms3.exe%22>Click here to download
RMS</a><br>")
End If
If Request.Form("swadv") > 0 Then
Response.Write("<a href=%22http://myurl/swadv.exe%22>Download Switching Advisor</a><br>")
End If
If Request.Form("tplan") > 0 Then
Response.Write("<a href=%22http://myurl/tplan.exe%22>Download Traffic Planner</a><br>")
End If
If Request.Form("city") > 0 Then
Response.Write("<a href=%22http://myurl/citycrew.exe%22>Download City Crew
orders</a><br>")
End If
%>
There are two problems:
1. If the item in question was never ordered, and the Session variable never
created, I get an error in the Response.Write line for that item:
Microsoft VBScript runtime error '800a000d'
Type mismatch: '[string: ""]'
(The line executes properly if the item was ordered.)

2. The url in the output is fubar: it is doubled, with the local url followed
by the correct url.

Sorry for the verbosity. Can you point me in the right direction?