Accessing Values Of Local Variables

I have created a nice funky 500 - 100 error page which gives a nicer error; happily loops through and supplies querysting information, all headers, server variables..etc but it has a limitation. On a normal error page you can always use a response.write then
response.end to look a the value of a local variable.

What I would LOVE would be to be able to loop through all the local variables (not
form or querystring, they're sorted) on the previous page and display their values so a developer would see the complete state of the page on the error page without having to use any on error statements. Has anyone achieved this, I can't think of a way at all.