/// <summary>
/// Validate the user input.
/// </summary>
/// <returns>false if there is invalid input, true if all input is valid.</returns>
private bool ValidateUserInput()
{
bool isValid = true;
_errors.ClearErrors();
if (String.IsNullOrWhiteSpace(Username))
{
isValid = false;
_errors.SetError(textBoxUsername, "A username is required.");
}
if (String.IsNullOrWhiteSpace(Password))
{
isValid = false;
_errors.SetError(passwordBoxPassword, "A password is required.");
}
return(isValid);
}