Welcome to PHPBuilder. Or, what's left of it We're just people who use PHP --- some professionals, some amateurs, and yes, even some "newbies". I sympathize with your troubles; debugging can, at times, be harder than it seems it should. And, like it or not, programming is Real Work(tm), and Real Work(tm) isn't always (perhaps "is hardly ever") easy.
I'm just guessing, but I think we'll need some more information if you really want help from a forum like this. If you just want someone to read all your code and sort the problem for you, I'd (gently, of course) suggest that you look for a freelance professional if you really want this done Real Soon Now(tm).
So, what have your tried? What symptom causes you to think it doesn't work? (It's not that the rest of us don't believe you, but the rest of us haven't witnessed the problem and we might have a better chance helping with that information available).
Are you using PHP for certain in your site? If so, you don't need to post the ASHX file here (that file, as you may have seen, is written in C# instead of PHP and there are very few here who know much about that).
Are there any error messages, or do you receive a blank page from the browser? Are there logs on the server that can tell you anything about the problem? Do you have tech support at your webhosting company?