how to call url of any other website in php.
use curl php library: http://php.net/manual/en/book.curl.php
direct example: CURL_EXEC
Check out the PHP cURL functions. They should do what you want.
Or if you just want a simple URL GET then:
$lines = file('http://www.example.com/');
As other's have mentioned, PHP's cURL functions will allow you to perform advanced HTTP requests. You can also use file_get_contents to access REST APIs:
$payload = file_get_contents('http://api.someservice.com/SomeMethod?param=value');
Starting with PHP 5 you can also create a stream context which will allow you to change headers or post data to the service.
The simplest way would be to use FOpen or one of FOpen's Wrappers.
$page = file_get_contents("http://www.domain.com/filename");
This does require FOpen which some web hosts disable and some web hosts will allow FOpen, but not allow access to external files. You may want to check where you are going to run the script to see if you have access to External FOpen.
If you meant .. to REDIRECT from that page to another, the function is really simple
header("Location:www.google.com");