How to disable the GUI.horizontalSlider?

Hi,

On my interface, I've got a couple of GUI.verticalslider and a GUi.horizontalslider. At some point the user can open an info page. The page is a label with a close button and on the bg I've got a fullscreen transparent black background (that separates the page and the interface).

I've got a simple bool called pageOnOff which is connected to the page and every button of my interface as:
if(GUI.button()!pageOnOff)
That way when the page is ON you can't click on the buttons.

How can I block the user from using the sliders the same way ?

Thanks a lot for the help

B.