Animated texture

I'm trying to write a very simple Script controller to animate a texture.

The texture's UOffset, Voffset and W-Angle need to be animated randomly.

No problem there, I did this :

random 0 100 for the U and V offset and degToRad (random 0 360) for Rotation.

But now I'm trying to find a way to only change it each 2 frames, so it doesn't move too fast. I tried using the frame number and checking if it's even (with mod operator) but I'm kinda stuck...

Any ideas on how I should approach this?