This really depends on what browser you are using. For Mozilla and Fire$ANIMAL, there is liveheaders, which displays the sent headers in a separate window. If you are using another browser, you might want a proxy which dumps all traffic going through it. Such a proxy could be written with HTTP::Proxy for example, but other solutions are also possible, by simply sniffing all traffic with ethereal or Net::PCap.

Even if you are using WWW::Mechanize, it's not a panacea - there will come a time when you really need to see what the differences are to make WWW::Mechanize mimic a specific browser in the closest possible way.

Many thanks. Liveheaders is genius! Really easy to spot where I went wrong. It was a set of spaces in another field that was shifting al the following pairs out of sync. All sorted now. Thanks again

Thanks very much. Liveheaders is genius! It was a load of spaces in another field that was throwing it. Turns out those two lines were fine! Working fine now.