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;
             }
 }