It will only check to see if the button is pressed and the text reads "O K" in the btnAction_Click event. 'If btnAction.Text = "O K" Then' does not check for button press, only text on button.
The purpos of a Button object is to get a user action done when clicking on it which calls the Button_Click event routine.
The Button.Text property is used to tell the user what his action will do.
In MyFirstProgram from the Beginner's Guide I use the same button for two different actions and use the Button.Text property to know what action to do in the Click event.