php man page for ob_flush

OB_FLUSH(3)								 1							       OB_FLUSH(3)

ob_flush - Flush (send) the output buffer

SYNOPSIS
       void ob_flush (void  )

DESCRIPTION
	This  function will send the contents of the output buffer (if any). If you want to further process the buffer's contents you have to call
       ob_get_contents(3) before ob_flush(3) as the buffer contents are discarded after ob_flush(3) is called.

	This function does not destroy the output buffer like ob_end_flush(3) does.

RETURN VALUES
	No value is returned.

SEE ALSO
       ob_get_contents(3), ob_clean(3), ob_end_flush(3), ob_end_clean(3).

PHP Documentation Group 													       OB_FLUSH(3)