Get thumbnail images from album using fql

I'm trying to get all the photos(thumbnail images) from specific album in facebook. I am trying to get it with fql.

But it gives me error开发者_StackOverflow code 601. Can anybody put down the query to get through this.

This is my code.

NSString *query=[NSString stringWithFormat:@"SELECT pid FROM photo WHERE aid IN ( SELECT aid FROM album WHERE owner=%@)",appDelegate.userID];
NSString *urlString = [NSString stringWithFormat:@"https://api.facebook.com/method/fql.query?format=json&query=%@&access_token=%@",[query stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding],[appDelegate.access_Token stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];

You need the user_photos extended permission.