Mini Blend Calculator

Well, Im trying to create a four function calculator with blend, but its kinda hard without a reference, so ill ask here.

This is how it looks like.

The little box at the right end is a label that displays the number.

So im trying to use one event, which comes from the “calculate” button. Here is the event code just for the addition.

        private void click(object sender, System.Windows.RoutedEventArgs e)
        {
            if (RadioButton.Content == "Addition")
            {
                DiaplayNumber.Content = double.Parse(FirstNumber.Text) + double.Parse(SecondNumber.Text);                
            }
        }

Thats my crack at it… it obviously doesn’t work. Any help?