Login con Facebook SDK para JavaScript[Unanswered]

$(document).on("click",'.fb-log',function(event){
	var
		curldata = $(".fb-log").attr("data-url"),
		dataurl = $("#data_url").val();
	event.preventDefault();
	FB.login(function(response){
		validarUsuario(curldata, dataurl);
	}, {scope: 'public_profile, email, user_birthday'});
});
function validarUsuario(curldata, dataurl) {
	FB.getLoginStatus(function(response) {
		if(response.status == 'connected') {
			FB.api('/me?fields=id,name,email,birthday,permissions', function(response) {
				var user = response;
				user.picture = "https://graph.facebook.com/"+user.id+"/picture";
				var
					nickname = response.name,
					username = response.email,
					password = response.id,
					birthday = response.birthday,
					picture = "https://graph.facebook.com/"+user.id+"/picture",
					data = "fb=1&username="+username+"&password="+password+"&nickname="+nickname+"&birthday="+birthday+"&picture="+picture+"&url="+curldata;
				alert(response.id);
				$.ajax({
					type: "POST",
					url: dataurl,
					data: data,
					dataType: "HTML",
					processData: false,
					cache: false
				}).done(function(data){
					$(".fb-log").html("Conectado.");
					alert(data);
				});
			});
		} else if(response.status == 'not_authorized') {
			alert('Debes autorizar la app!');
		} else {
			alert('Debes ingresar a tu cuenta de Facebook!');
		}
	});
}

<?
	session_start();
	include "config.php";
	if (isset($_REQUEST['error_reason'])) {  
		echo("<script>self.close();</script>");  
		exit;  
	}
	$fb = $_POST["fb"];
	$username = $_POST["username"];
	$password = sha1($_POST["password"]);
	$nickname = $_POST["nickname"];
	$birthday = $_POST["birthday"];
	$picture = $_POST["picture"];
	$url = $_POST["url"];
	if(isset($fb) === 1){
		$sql_fb = "SELECT username FROM usuarios WHERE username=".$username;
		$query_fb = mysqli_query($con, $sql_fb) or die (mysqli_error($con));
		if (mysqli_num_rows($resultado)>0){
			
			$jsondata = true;
		}else{
			$insert = "INSERT INTO usuarios (nickname, username, password, birthday, picture) VALUES ('$nickname', '$username', '$password', '$birthday', '$picture')";
			mysqli_query($con, $insert);
			$jsondata = false;
		}
		//echo json_encode($jsondata);
	}
?>