Response Header "If-Modified-Since"

How the heck do I use it?

[HyperGeek]

According to this thread...

[webmasterworld.com ]

...we should be adding...

If-Modified-Since = "If-Modified-Since" ":" HTTP-date

...to our web pages to help the spider/caching process.

Now, not being familiar with response headers I need someone to give me bearing on what they are and how I can implement them in to the sites I design. (I'm totally self-taught, so a few things slip by if not in the books I've read - grasping this seems very important).

I've tried just pasting the code in to the page, but I'm missing something. Is this server-side code? What are the actual tags I would use to make this work? Is it even something I put in the page itself or is it something completely different?

Please advise!

[wkitty42]

the first question is what http server are you operating on?

the second question is do you have access to the configs of that server?

the third question is are you actually meaning the "Last-Modified:" header instead?

[jdMorgan]

wkitty,
Yes, that's part of the confusion. Since GG thinks in http-client terms, he's telling us to support If-Modified-Since. But since we're on the server end end, this translates into making sure our servers are configured to return correct Last-Modified and Expires headers, and to respond properly to Conditional GET requests.

Hypergeek,
The Server Headers Checker [webmasterworld.com] is useful for testing whether appropriate Last-Modifed and Expires headers are returned.

Jim

[wkitty42]

that's what i was thinking, jdMorgan... thanks...

now, can you tell me why i can't get into that thread that hypergeek posted? each time i try, i'm presented with a login page but i'm already logged in... cookies are accepted... FWIW: i'm not at my normal location... viewing from another location with (ugh) IE6 instead of my normal mozilla...

[jdMorgan]

Yes, strange...

That link picked up some extra variables somehow... Try this one [webmasterworld.com] instead.

Jim