Expression help? Changing opacity and holding the value for 2 seconds

[defaultjl6p4as1bj8g]

I have a box (shape layer) that I want to change the opacity to a random number between 0-100, then hold that opacity value for 2 seconds, then change the opacity value again to another random value, and so on...
 
Any ideas where I could find a quick copy/paste expression? Thank you. 

[Mylenium]

seedRandom(Math.floor(time/2);

random(0,100);

Mylenium 

[defaultjl6p4as1bj8g]

Thank you, however, I am still seeing a new random opacity every frame. I also added another parentheses after (time/2)); 

Any other ideas?

[Mylenium]

Yeah, my bad. Damn auto-correct when typing on the tablet. 😉

Mylenium 

[Dan Ebberts · Accepted solution]

I'd do it like this:

holdTime = 2;
seed = Math.floor((time - inPoint)/holdTime);
seedRandom(seed,true);
random(100);

[defaultjl6p4as1bj8g]

That's it! Thank you!