$internal = false;
$internal_ip_start = "152";
if(strlen($REMOTE_ADDR)>0)
{
$temp_ip = split(".",$REMOTE_ADDR);
if(strcmp($temp[0],$internal_ip_start)==0)
$internal = true;
}
if(!$internal)
{
header("Location: your_new_page_for_externals");
exit;
}
else
{
header("Location: your_new_page_for_INTERNALS");
exit;
}