Session problem

[atu]

Hi,
When starting session_start() after ob_start(); there is always some unwanted crap code before the real output. When session_start() is before ob_start() it's ok.

Why?

[St.]

case ob_start() starts writing all outputs into memory.
with ob_flush() you can send all of code from memory writed after ob_start().
but session_start() is starting session. It means not only send header to user, but it fetchs $_SESSION variables.
How I understend, if you start session_start() before ob_start(), $_SESSION variables in realy will fetch after ob_flush().

[atu]

The problem was solved as follows;

<?php

ob_start();

//.......

ob_start();
session_start();
ob_end_flush();

//.......

ob_end_flush();

?>

But there is still this question; Why?