Okay, I'm going to update this posting a little to see if I get any bites. I have made the page in question a standard VBScript page, blocking out the jscript code with <script language="JScript" runat="Server"> opening and closing tags. This essentially covers the entire page. About midway down the page I have a function that calls upon the vbscript include file. When I run the page now, I get an Object Expected error.
If I split up the code, so that there are blocks of Jscript <script> code on either side of where the vbscript code calls the include function, nothing gets passed from the jscript code to the vbscript code (and then back to the jscript code). In other words, I have a string variable that originates in the jscript block, then must go to the vbscript include file, and then come back and do something else in the jscript block. Right now, nothing's getting passed between the different <script> blocks.