This is a standard normal HTTP request

GET / HTTP/1.1
User-Agent: curl/7.20.1 (x86_64-redhat-linux-gnu) libcurl/7.20.1 NSS/3.12.6.2 zlib/1.2.3 libidn/1.16 libssh2/1.2.4
Host: www.google.com
Accept: */*

HTTP/1.1 200 OK
Date: Thu, 10 Jun 2010 17:22:54 GMT
Expires: -1
Cache-Control: private, max-age=0
Content-Type: text/html; charset=ISO-8859-1
Set-Cookie: PREF=ID=5e8e80a9e66b65a2:TM=1276190574:LM=1276190574:S=UwbV5O8HJMVqISMc; expires=Sat, 09-Jun-2012 17:22:54 GMT; path=/; domain=.google.com
Server: gws
X-XSS-Protection: 1; mode=block
Proxy-Connection: close

This is a 404 error HTTP request

GET /thisisa404.html HTTP/1.1
User-Agent: curl/7.20.1 (x86_64-redhat-linux-gnu) libcurl/7.20.1 NSS/3.12.6.2 zlib/1.2.3 libidn/1.16 libssh2/1.2.4
Host: www.google.com
Accept: */*

HTTP/1.1 404 Not Found
Content-Type: text/html; charset=UTF-8
X-Content-Type-Options: nosniff
Date: Thu, 10 Jun 2010 17:23:35 GMT
Server: sffe
Content-Length: 1369
X-XSS-Protection: 1; mode=block
Proxy-Connection: Keep-Alive