share to facebook error

kindly when i use the following code :- fb.requestWithGraphPath('me/feed', {message: "Trying out FB Graph API and it's fun!"}, "POST", function(e) { if (e.success) { alert("Success! From FB: " + e.result); } else { if (e.error) { alert(e.error); } else { alert("Unkown result"); } } });

i get he following error :-

An active access token must be used to query information about the current user.

any one have a solution ????

thanks,