ob_flush in PHP

ob_flush — Flush (send) the output buffer
Syntax: void ob_flush ( void )
This function will send the contents of the output buffer (if any). f you want to further process the buffer's contents you have to call ob_get_contents() before ob_flush() as the buffer contents are discarded after ob_flush() is called.
This function does not destroy the output buffer like ob_end_flush() does.

Return Values:No value is returned.