Pressing the Tab or Return key in some fields will elicit some useful actions that help you to complete the fields. Such actions vary depending on the characteristics of data. For example, pressing the Tab or Return key in the ID field will check whether the ID just typed has been registered. If so, the other fields of the Patient page will be filled with data retrieved from the patient database automatically. This action will not only reduce the number of your key strokes, but also keep you from inserting wrong or invalid IDs. Be sure to press the Tab or Return key after completing fields that are labeled as Action Field in the following sections.