func showLoginSignUp(){
    var loginAlert:UIAlertController = UIAlertController(title: "Please Login",       message: "Please sign up or login", preferredStyle: UIAlertControllerStyle.Alert)

    loginAlert.addTextFieldWithConfigurationHandler({
    textfield in
    textfield.placeholder = "Your username"
    })

    loginAlert.addTextFieldWithConfigurationHandler({
    textfield in
    textfield.placeholder = "Your password"
    textfield.secureTextEntry = true
    })

    loginAlert.addAction(UIAlertAction(title: "Login", style: UIAlertActionStyle.Default, handler: {
    alertAction in
    let textFields:NSArray = loginAlert.textFields! as NSArray
    let usernameTextfield:UITextField = textFields.objectAtIndex(0) as UITextField
    let passwordTextfield:UITextField = textFields.objectAtIndex(1) as UITextField

    PFUser.logInWithUsernameInBackground(usernameTextfield.text, password: passwordTextfield.text){
    (user:PFUser!, error:NSError!)->Void in
    if ((user) != nil){
    println("Login successful")
    var installation:PFInstallation = PFInstallation.currentInstallation()
    installation.addUniqueObject("Reload", forKey: "channels")
    installation["user"] = PFUser.currentUser()
    installation.saveInBackground()

    }else{
    println("Login failed")
    }


    }




    }))

    loginAlert.addAction(UIAlertAction(title: "Sign Up", style: UIAlertActionStyle.Default, handler: {
    alertAction in
    let textFields:NSArray = loginAlert.textFields! as NSArray
    let usernameTextfield:UITextField = textFields.objectAtIndex(0) as UITextField
    let passwordTextfield:UITextField = textFields.objectAtIndex(1) as UITextField

    var sweeter:PFUser = PFUser()
    sweeter.username = usernameTextfield.text
    sweeter.password = passwordTextfield.text

    sweeter.signUpInBackgroundWithBlock{
    (success:Bool!, error:NSError!)->Void in
    if !(error != nil){
    println("Sign Up successfull")


    var installation:PFInstallation = PFInstallation.currentInstallation()
    installation.addUniqueObject("Reload", forKey: "channels")
    installation["user"] = PFUser.currentUser()
    installation.saveInBackground()


    }else{
        let errorString = error.localizedDescription
        println(errorString)

    }


    }



    }))

    self.presentViewController(loginAlert, animated: true, completion: nil)
    }