Changing shaders of a GameObject via script

Hi , I have a gameobject that have 5 materials with diffuse shaders. I want to changing the shaders of all from diffuse to Trasparent/Diffuse. By bellow code i can only change one shader. how can i access all shaders and change them? maybe with using an array.

var shader1 : Shader;
var shader2 : Shader;

function Start(){
    shader1 = Shader.Find( "Diffuse" );
    shader2 = Shader.Find( "Transparent/Diffuse" );

function Update() {
    if (Input.GetKeyDown("f")) {
        if( renderer.material.shader == shader1 )
            renderer.material.shader = shader2;

You can access the renderer’s materials property which holds all the materials, then change them one by one.