///
        /// <summary>   Event handler. Called by AddressTextBox for text changed events. </summary>
        ///
        /// <remarks>   2019-04-20. </remarks>
        ///
        /// <param name="sender">   Source of the event. </param>
        /// <param name="e">        Text changed event information. </param>
        ///

        private void AddressTextBox_TextChanged(object sender, TextChangedEventArgs e)
        {
            bool isValid = true;

            //Ensure valid address
            isValid = PatientValidation.ValidateAddressLine1(addressTextBox.Text);

            if (!isValid && !String.IsNullOrEmpty(addressTextBox.Text)) //Not valid and not empty
            {
                addressBool             = false;
                addressError.Visibility = Visibility.Visible;
            }
            else //valid
            {
                addressBool             = true;
                addressError.Visibility = Visibility.Hidden;
            }
        }
        /// <summary>   Event handler. Called by AddressTextBox for text changed events.
        ///             Ensure a vlaid address, otherwise set it to blank</summary>
        ///
        /// <remarks>   2019-04-20. </remarks>
        ///
        /// <param name="sender">   Source of the event. </param>
        /// <param name="e">        Text changed event information. </param>

        private void AddressTextBox_TextChanged(object sender, TextChangedEventArgs e)
        {
            SubmitError.Visibility = Visibility.Hidden; //Hide the error initally
            bool isValid = true;

            //Validate address
            isValid = PatientValidation.ValidateAddressLine1(addressTextBox.Text);

            if (!isValid && !String.IsNullOrEmpty(addressTextBox.Text)) //If it is not valid and not empty
            {
                addressOne = "";                                        //Address is not set. Error is shown
                addressError.Visibility = Visibility.Visible;
            }
            else //Valid address. Set the address to the textbox string
            {
                addressOne = addressTextBox.Text;
                addressError.Visibility = Visibility.Hidden;
            }
        }