Creating Object Arrays

at the moment i am testing arrays for a turn based style game but i cant get the hang of object arrays, how do you get an object into an array iv made some objects in my hierarchy but i can seem to get them into arrays do they need to be prefabs to go into arrays
so far iv got this

var plates : GameObject;

function OnGUI(){

if(GUI.Button(Rect(10,10,100,50),“Click”)){
Debug.Log(“next step”);

}

plates = [X1,X2];

}

You should read this:
http://unity3d.com/support/documentation/ScriptReference/Array.html

You need to add the values to the array, im a bit rusty on Javascript so I will try my best to show you.

//Declare the array and make it a float
var aFloat: float[];

function Start () {
    //Initialize it
	aFloat = new float[5];
}


function OnGUI(){

if(GUI.Button(Rect(10,10,100,50),"Click")){ Debug.Log("next step");

}
//Add to the 1st slot of the float (Which is always 0) so in this case this float
//will be from 0-4.
aFloat[0] = 1.2;

}

If you explain what you are trying to do and what X1, X2 are I can give you a much better example.