my checkboxes are null references

hey there,

At one point in my code I have this:

            var chkboxSells = new CheckBox
            {
                Text = "Sells",
                HorizontalAlignment = HorizontalAlignment.Left,
                VerticalAlignment = VerticalAlignment.Center,
                IsChecked = false
            };

and later on i have this..

var includeSells = chkboxSells.IsChecked;

but i've also tried this and a  zillion variations..

           var includeSells = chkboxSells != null && (bool)chkboxSells.IsChecked;

in the first attempt i get crashes due to null object references, and in the 2nd I can never get a checkd result to come through as true

Can anyone help me understand how to handle this?