Random Position Script

I'm making a script to generate power-ups. So far this is what I have:

    var prefab :  Transform;
var timer = 10.0;
var countdown = 1.0;
var xpos = 0;
var ypos = 0;
var zpos = 0;

function Update () 
    {
    if (timer > 0)
        {
        timer -= countdown * Time.deltaTime;
        }
    if (timer < 0)
        {
        timer = 0;
        }
    if (timer == 0)
        {
        Instantiate (prefab, Vector3(xpos, ypos, zpos), Quaternion.identity);
        timer = 10.0;
        }
    }

How can I impliment a function that will cause the position of the objects spawn to change each time? I need to be able to change the variables xpos and zpos (x and z posisions) to anywhere from 0 to 25. I know the Range function will do this, but I don't know how to correctly type the script. Can someone show me a simple script to generate a random number from 0 to 25?

var rx = Random.Range(0,25); // integer
var rx = Random.Range(0.0,25.0); // float

Did you look at http://unity3d.com/support/documentation/ScriptReference/Random.Range.html ?