I ended up using a simpler method. Here is my script:

    #pragma strict
//Setting the images for each of the 3 Button Stages
var NormTex : Texture2D;
var HighTex : Texture2D;
var DownTex : Texture2D;

// To check if the mouse is over the button
var over : boolean = false;

//Set it to normal on start
function Awake(){
 renderer.material.mainTexture = NormTex;
 }

/*If the mouse is over it, set the texture to highlighted
Note: To save CPU, it is "OnMouseEnter" as opposed to "OnMouseDown", which would be called
Every frame the mouse is over the plane.*/

function OnMouseEnter(){
 over = true;
 renderer.material.mainTexture = HighTex;
 }

// Changes back to normal on the exit

function OnMouseExit(){
 over = false;
 renderer.material.mainTexture = NormTex;
 }

// Changes to click graphic on click

function OnMouseDown(){
 renderer.material.mainTexture = DownTex;
 }

//Changes the button back based on wether or not the mouse is over it
//This may be unnecessary but eliminates the possibility of it being screwed up

function OnMouseUp(){
 if(over){
 renderer.material.mainTexture = HighTex;
 }else{
 renderer.material.mainTexture = NormTex;
 }
 }

look up ray casting, http://docs.unity3d.com/Documentation/ScriptReference/Physics.Raycast.html