How to get access token Facebook

How to get access token Facebook

how to get access token on facebook?
I Already have the following things: 1. The App id 2. Secret Code for the App
Php setup to get the likes as stated below
mysql_real_escape_string($web[$i]);
$site="http://graph.facebook.com/?ids=".$web[$i]."";
$graph= file_get_contents($site);
$json_string=$graph;
$array = json_decode($json_string, true);
$var[$i] =($array[$web[$i]]['shares']);
Can anyone please guide me thorough?