Page 2 - Minimum bandwidth for a HTTP request

that would be ideal, if I could keep the page from loading but still send variables - but how to circumvent the max_execution_time?

set_time_limit()

(but can be disabled by server admin)

A friend of mine made a server-side chat application that worked using cookies attached to an image. I don't have all the details and his site is no longer up, but it worked like this:

1. The client checks (using Javascript) to see if there are any messages by setting an image variable to the url of the php page that checks for messages.
2. If there are messages, the php page sends back a small token image with the messages attached as cookies.
3. If there are no messages, it sends back no image.
4. To post a message just request an "image" using the url of the posting php page with the message in the query string.

So, the only wasted communication is the request for an image every x seconds and the null image for an empty reply.

not true. you didn't count headers sent both ways. even if you dont send the image back, headers are sent, and that is what mungane's problem was originally.

he used javascript that didn't send anything when there are no new messages. but that "nothing" is still "nothing with headers" ;)