     
     @IBAction func loginButtonAction(sender: UIButton) {
         
-        if ((txtLogin.text != nil && txtPassword.text != nil)) {
+        if ((txtLogin.text!.isEmpty || txtPassword.text!.isEmpty)) {
             let alertController = UIAlertController(title: "On The Map", message:
-                "Please fill both the username and password fields", preferredStyle: UIAlertControllerStyle.Alert)
+                "Please fill both the username and password fields.", preferredStyle: UIAlertControllerStyle.Alert)
             alertController.addAction(UIAlertAction(title: "Dismiss", style: UIAlertActionStyle.Default,handler: nil))
             
             self.presentViewController(alertController, animated: true, completion: nil)

        let session = NSURLSession.sharedSession()
        
        let task = session.dataTaskWithRequest(request) { data, response, error in
            
            if error != nil { // Handle error
                
                return
                
            }
            
            let newData = data?.subdataWithRange(NSMakeRange(5, data!.length - 5)) /* subset response data! */
            
            print(NSString(data: newData!, encoding: NSUTF8StringEncoding))
            
        }
        

import FBSDKCoreKit
import FBSDKLoginKit
import FBSDKShareKit
import SwiftyJSON

class ViewController: UIViewController, FBSDKLoginButtonDelegate {
    @IBOutlet weak var txtLogin: UITextField!
