When you create a modal dialog, decide how the dialog will be displayed and closed. Since a modal dialog requires input from the end user, its content canvas always should contain navigable items. For this reason, the simplest way to display a modal dialog is through navigation from an item in the current window to the first navigable item in the dialog window. When such navigation occurs, Oracle Forms automatically displays the window (in this case, the modal dialog) that contains the target item.
The navigation event might be the end user pressing the Tab [Next Item] key, or, more likely, a button trigger or menu command that navigates programmatically. For example, you might call the NEXT_BLOCK, GO_BLOCK, or GO_ITEM Built-ins from a When-Button-Pressed trigger to navigate to a target item in the dialog.
You can also execute the SHOW_WINDOW Built-in to display the modal window. When you use SHOW_WINDOW to display a modal window, it implicitly navigates to the first navigable item on the canvas for that window.
You can invoke a modal window from another modal window. For example, the standard Microsoft Windows Printer Setup modal dialog has an Options button that invokes a second modal dialog. When a modal window has been invoked from another modal window, navigation to any modeless window in the same form automatically closes both the parent and child modal windows.