How to Insert a Dropdown List Box or Combo Box

The difference between a dropdown list box and a combo box is that a dropdown list only allows the end user to choose a pre-defined option from a list, while a combo box allows the end user to either choose an option from the list, or type in a value.

You can create a dropdown list box:

·	In the Definer, by using the Dropdown List Box display type for a domain.

·	In the Windows Designer, by inserting a dropdown list box or combo box control class into a window or dialog.

Combo boxes can only be created in the Windows Designer.

If you create the control using the Dropdown List Box display type, allowed values must be defined at domain level. In this case, the dropdown list box appears automatically after synchronization.

If you create the control in the Windows Designer, the values on the list can either be hard-coded, or retrieved from the database by means of a SQL statement or Related Column.

To insert a dropdown list or combo box using the Windows Designer:

1.	Use the Windows Designer catalog to open the appropriate window/dialog.

2.	In the design view, select the object into which you want to insert the dropdown list or combo box.

3.	From the menu bar, choose Insert, List, and then choose Dropdown List or Combo Box.

4.	Make sure the Selection Filter option from the View menu is turned on, select the Dropdown List or Combo Box object, and then open the Property Inspector.

If you inserted a Combo Box object and want to turn it quickly into a Dropdown List object, set the Check List property to Yes (the reverse is also possible).

5.	Change the Prompt, Data Length, and Default Value properties on the General tab page of the Property Inspector to suit your needs.

6.	Depending on whether you want to hard code the values on the dropdown list/combo box or retrieve them from the database, set the Value List property, or the Values to Query property. You can also use a Related Column.

If you use the Value List property, separate the values by means of "returns" (either use SHIFT+ENTER, or CTRL+ENTER). If the actual values are not the same as the prompts you want to use, set the Value List Prompts property (again use returns to separate the values).