Now you download your facebook sdk .
1)unzip the facebook sdk folder to /www/newfolder
2)open editor
3)Now type this simple program
<?php
include(“src/facebook.php”);
$h=new Facebook(
array(‘appId’=>’you app id’,’secret’=>’your secret id’,’cookie’=>true);
);
$h=$facebook->getUser();
$me=null;
if($h)
{
try{
$me=$facebook->api(‘/me’);
}
catch(FacebookApiException $e){
echo $e->getMessage();
}
}
if($me)
{
$logoutUrl=$facebook->getLogoutUrl();
echo “<a href=$logoutUrl>Logout</a>”;
}else
{
$loginUrl=$facebook->getLooginUrl(array(‘scope’=>’publish_stream’));
echo “<a href=$loginUrl>Login</a>”;
}
?>