First, the browser can indeed handle the cookie header and the "Location: ..." header line in the same server response. The Location line must come last and it must end with two new-lines.

But I can find no indication in my quick re-visiting of the docs that the CGI redirect function allows the specification of a cookie along with the redirect. (Update: but see the following response by athomason.) And the CGI pod says don't print a header along with a redirect.

So I accomplish this manually:

  print "Set-Cookie: $usr=x;expires=-1d\n";
  print "Location: http://mypage.com/my_login.html\n\n";
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BTW, are you sure that $in{usr} and $usr have the same value? That would, of course, be crucial to what you are trying to do.