Script to autoassign a script to objects

This is what i got but it gives me the old “object reference not set as an instance of an objec” error:

function Start () {
	 var renders : GameObject[] = FindObjectsOfType(MeshRenderer) as GameObject[];
	 for (var render : GameObject in renders){
		var script : wireframe;
		script = render.AddComponent("wireframe");
		 }
}

Can anybody help?

EDIT: the problems seems that I’m trying to access only the game objects that have a mesh renderer: apparently is not done this way.

i got it working:

function Start () {
	 var renders : GameObject[] = FindObjectsOfType(GameObject) as GameObject[];
	 for (var render : GameObject in renders){
		var script : ScriptName;
		if (render.renderer){
		script = render.AddComponent("ScriptName");
		}
		 }
}