Header Transfer-Encoding: Chunked?

How is this done? Using PHP Flush?

[Parlays]

I have been looking at the headers of several sites such as Yahoo Search. They show that they are using 'Content-Encoding:Gzip' and 'Transfer-Encoding:Chunked'.

How do they use chunked encoding while using gzip? Are they using the PHP flush() function?

My PHP flush function doesn't work on my dedicated server with Apache 2 even though I disabled gzip? But it works on my shared hosting server that is running Apache 1.3