How to send/get data with other server by POST/GET method choose only one. and that server have to reply the result of XML script. I would like to check the status from the other server.

Such as,
My server IP address is (Example IP)
The other server IP address is (Example IP)

The other server have the firewall and it had already open the firewall for my IP Address.

But when i try to send data to that server. It will show ISP IP address ( and display,

Ex. XML reply

<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE content ....................>
<detail>Request IP access denied</detail>

Ex. my PHP

header("Content-type: text/xml\n");
header("Location: pid=xxxxx");

I think may i must use the function about XML but i had to read the PHP manual i don't understand it.
Pls, recommend me about that.