Looking for some Javascript help with buttons

Using Adobe Acrobat X Pro, I would like the user to be able to click repeatedly on a single button  in order to turn on and off the visibility of different objects or buttons, and the following cycle to happen:

• With the first click, button one becomes visible.
• With the second click, button two also becomes visible.
• With the third click, both buttons are hidden.
• With the fourth click, button one becomes visible.
• With the fifth click, button two also becomes visible.
• With the sixth click, both buttons are hidden…
• …and the cycle continues.

I have the code (below) that nearly does the trick, but I don’t want colours changing and would like to amend the code to replace the colour coding with a variable.  However I cannot get this to work, as I don’t really know the syntax for setting global variables.  E.g. I want to set a “behind the scenes” variable such as A, B, C that changes to the next letter on each click (with C going to A).  This variable can then be used to go through the above cycle accordingly.

[background:  there are more states than 3, but simplified for purposes of posting.  Also this will need to be done in around 100 places, which is why I want a neater “variable” solution than changing colours!]

if (color.equal(event.target.fillColor, color.red))

{button1.display = display.visible;

event.target.fillColor = color.yellow;}

else if (color.equal(event.target.fillColor, color.yellow))

{button2.display = display.visible;

event.target.fillColor = color.green;}

else {event.target.fillColor = color.red;

button1.display = display.hidden;

button2.display = display.hidden;}