This is just an idea and I'm sure someone will have a way around this. But when you display the form, set a cookie with a known, difficult to guess value. When you process the form, check for the existance of that cookie. If someone is posting from another domain they won't have have that cookie.

You can also check the refering URL, but that can be spoofed I think.

In reply to Re: Thwarting Screen Scrapers by Abstraction
in thread Thwarting Screen Scrapers by kschwab

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