How to bind <toolkit:ListPicker in windows phone

<toolkit:ListPicker>

<pre>string strSelect = "SELECT UserTypeID, UserTypeDesc FROM UserTypes";
            _customerEntries = (Application.Current as App).db.SelectObservableCollection<Customer>(strSelect);
            string u = "";
            foreach (Customer data in _customerEntries)
            {
                 
                listUserType.Items.Add(data.UserTypeDesc);
            }