Use Dialog to configure the find-and-replace dialog before the action fires or to close the modeless dialog programmatically. For example, you can set the dialog's options at design time using the Object Inspector or call the dialog's CloseDialog method to shut down the modeless find-and-replace dialog. 

When using a search/replace action, you do not place a TReplaceDialog component on the form or data module at design time. Instead, you add the TSearchReplace action to your action list and then use the Dialog property. The TReplaceDialog component is created by the TSearchReplace constructor. 

ExecuteTarget 

CloseDialog