flush php command in VBulletin

[marianowo]

Hi
I´m new with VB and PHP.
Why don´t work the flush(); php command in a page that i created in my vbulletin site?
Somebody can help me?
If I execute this code in a popup windows, it works but not inside the vbulletin page.
my code is like this:

echo "<textarea name=\"textfield\" cols=\"90\" rows=\"20\" readonly
class=ta wrap=\"VIRTUAL\">\n";
system("traceroute $host");
echo "</textarea>\n";
flush();

Thank you very much.