procedural terrain

hi, i wrote a JS script that randomly generates a cubic terrain using perlin noise and i have a few questions:

how would i make the height differences between cubes static? (i will all ways be the same)

You mean a seed? Simple!

Random.seed = Random.Range(int.MinValue, int.MaxValue);
// if 2d
offset = new Vector2(Random.Range(0, 10000), Random.Range(0, 10000));
// or this if 3d
offset = new Vector3(Random.Range(0, 10000),Random.Range(0, 10000),Random.Range(0, 10000));

So when you always put the same seed in Random.seed the offset will always be the same.
When you get your data from the perlin noise just add the offset to your coordinates.