Several ways to run a PHP script outside browser:
CLI (Command Line Interface)
Call your script like #php /path/to/your/script.php from terminal/CMD
Telnet/SSH (Same as above)
Crond
On *NIX systems there is something called CROND which allows you to execute scripts according to a schedule E.G. every hour, every day, the first monday of each month etc.
Look up CROND tutorials on Google and use the above CLI example as your script
#!
Not sure if this works but you may be able to run it by adding the line
#! /etc/php to the first line of your script then run it by double clicking (Only on Unix/Linux)
If I have not answered your question just say but those are the main ways of running scripts outside browser

thanks.good post.I am aware about setting up the cron but here we should not do that.
I did a script to run as a process and transferred it to some server using ftp, so we don't have remote access to that server.
So no double clicking the file, that way, though it seem to be a good option (thanks for it, i will like it to give a try sometime later,i just got to see it).
Hope i cleared the scenario , if not please ask, i will need to clarify.

If you only have basic FTP access I don't think its possible, some admin panels will let you do it (if you have one) but other than that no ideas so sorry =(

thanks, it's fine.I also feel now that, it must not be any way except using some external tools designed to execute the script remotely on that specific servers

There is another way if you have ssh access to the server and a local Linux machine. From the local Linux machine use rsh to invoke the script on the server. There are several tricks that can be employed here that would allow you to automate access to your server without requiring username and password, a search for Private/Public Key and known_hosts should do the trick. Just remember to set permissions on the script so that it is executable and as mentioned above ensure that the first line of the script identifies the PHP CLI runtime.

hey thanks moorlie, that's one nice too.by this time got so many things about PHP CLI.closing the thread

header("Pragma: public"); // required
header("Expires: 0");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Cache-Control: private",false); // required for certain browsers
header("Content-Type: application/octet-stream");
// change, added quotes to allow spaces in filenames, by Rajkumar Singh
header("Content-Disposition: attachment; filename=\"".basename($filename)."\";" );
header("Content-Transfer-Encoding: binary");
header("Content-Length: ".filesize($filename));
readfile("$filename");
exit();