I Need a texture changer

Unity Engine
1

I need a texture changer that can hold up to 20 textures without shading conflict.

(Calls textures to change in sequence with a function or functions)

2

Its your lucky day, here is my flag code

var Texture1 : Texture;
var Texture2 : Texture;
var Texture3 : Texture;
var Texture4 : Texture;
var Texture5 : Texture;
var Texture6 : Texture;
var Texture7 : Texture;
var Texture8 : Texture;
var Texture9 : Texture;
var Texture10 : Texture;
var Texture11 : Texture;

private var Startwaving :float;
var ChangeInterval :float  =0.15;

function Update () {

if (Time.time - Startwaving > ChangeInterval){

	if(renderer.material.mainTexture ==Texture1) renderer.material.mainTexture =Texture2;
	else if(renderer.material.mainTexture ==Texture2) renderer.material.mainTexture =Texture3;	
	else if(renderer.material.mainTexture ==Texture3) renderer.material.mainTexture =Texture4;	
	else if(renderer.material.mainTexture ==Texture4) renderer.material.mainTexture =Texture5;	
	else if(renderer.material.mainTexture ==Texture5) renderer.material.mainTexture =Texture6;	
	else if(renderer.material.mainTexture ==Texture6) renderer.material.mainTexture =Texture7;	
	else if(renderer.material.mainTexture ==Texture7) renderer.material.mainTexture =Texture8;	
	else if(renderer.material.mainTexture ==Texture8) renderer.material.mainTexture =Texture9;	
	else if(renderer.material.mainTexture ==Texture9) renderer.material.mainTexture =Texture10;	
	else if(renderer.material.mainTexture ==Texture10) renderer.material.mainTexture =Texture11;	
	else if(renderer.material.mainTexture ==Texture11) renderer.material.mainTexture =Texture1;	
	Startwaving=Time.time;

}

}