Note: This blog post is from 2011. Some content may be outdated--though not necessarily. Same with links and subsequent comments from myself or others. Corrections are welcome, in the comments. And I may revise the content as necessary.If you ever try to use CFHTTPPARAM (inside a CFHTTP) to set HTTP headers for the request you're calling, be aware that you need to be careful to specify the name of the headers as they're known in the HTTP specification. Don't be misled by what you see in a CFML dump of the CGI scope.
(This is a reprisal and update of an old blog entry I'd done back in 2003, on a blog site that will soon no longer exist. I'll be reprising a few such blog entries in coming days/weeks, to keep them around for posterity [and to save some having to dig for them in the archive.org site] since often the info offered then may be just as valuable now. I hope that in time these new versions would come up if people do searches that would have found the old entry.)
So, about these http headers, while CFML exposes them in a dump of the CGI scope, such as the user-agent field which shows up as cgi.http_user_agent, the issue is that you would not use that name, nor even "user_agent", when specifying it in a CFHTTPPARAM. The proper way to pass the user agent in a CFHTTPPARAM would be as follows: