In composing mail, I double click a contact from the contact pane, or drag to the To or Cc Field, or click and select the address field, but the address field remains blank, no name or address is displayed. Even when I write names in the Field, after typing some letters or characters, I expect Thunderbird to automatically complete the address but it does not do so. I wonder why the address field remains blank after using these options to enter addresses in the mail. The only one that works is my completing the address field manually, which is a frustrating task.