Call User control event from parent window WPF c#

//In userControl

public event EventHandler HelpButtonUpdated;

        public Header()

        {

            InitializeComponent();

        }

        private void Image_MouseDown(object sender, MouseButtonEventArgs e)

        {

            //Null check makes sure the main page is attached to the event

            if (this.HelpButtonUpdated != null)

                this.HelpButtonUpdated(new object(), new EventArgs());

        }

Main Window

  header.HelpButtonUpdated += new EventHandler(MyEventHandlerFunction_HelpButtonUpdated);

public void MyEventHandlerFunction_HelpButtonUpdated(object sender, EventArgs e)

        {

            PopupHelp.IsOpen = true;

            Opacity = 0.5;          

        }