Sets the ID of the default response of self.
If set, pressing <kbd>Enter</kbd> will activate the corresponding button.
If set to NULL or to a non-existent response ID, pressing <kbd>Enter</kbd> will do nothing.
the default response ID
Sets the ID of the default response of self.
If set, pressing <kbd>Enter</kbd> will activate the corresponding button.
If set to NULL or to a non-existent response ID, pressing <kbd>Enter</kbd> will do nothing.