CanExecute Requery

I have a textbox on a wpf form that has 2 buttons next and previous when the textbox is in error next is disabled.

cmdNextPage_CanExecute(object sender, CanExecuteRoutedEventArgs e)
{ 
 if (!textbox.GetBindingExpression TextBox.TextProperty).HasError)
 {
  e.CanExecute = true;
 }
}

I would like to use the CommandManager.InvalidateRequerySuggested() on the lost focus of the textbox so that I can enable the next button.

Is there a way to achieve this?