Triggered variable preventing user from revisiting slide

Hi All,

I write e-learning courses for some complex technical procedures, and set up the courses like this:

• Sections of the procedure are on individual slides (e.g., slide "Calibrate Widget")
• Steps of the procedure for that section are on slide layers (e.g., calibrate widget, step 1 is on layer 1; step 2 is on layer 2 etc.)

I have it set up so that when the slide timeline starts, layer 1 automatically shows - if the slide has not been visited. The user navigates through the slide layers with "continue" or "back" buttons at the bottom of the layers. When the last layer is completed, the "continue" and "back" buttons appear as in the other layers, but in this case when the continue button is clicked,  a variable of the project is adjusted (e.g., Widget_Calibration_Complete = True), and the slide base layer shows. Since the triggers are set such that layer 1 shows automatically if "Widget_Calibration_Complete = False, the main menu for navigating the other slides appears.

All that is working fine. However, what's tripping me up at the moment is that if someone wants to revisit the slide that they have already seen, it is not possible. Is there a way around this?