[Closed]GUI.DrawTexture inside GUI.DrawTexture

maybe it is an odd question but what i try to accomplish here is…

i create a GUI.DrawTexture showing a whiteboard, and here’s the code

public var background1 : Texture;
var btn_next : Texture;
function OnGUI(){

			(Screen.height-(Screen.height/4*3))/2, //this is to center the Rect
		        Screen.width/4*3, Screen.height/4*3),background1);

     //btn_next must be at right-lower corner of whiteboard.

and then i want to Draw again a texture of Next Button, but i want to Draw it Inside the background 1… so i will not put it bluntly on the screen… because it will cause the button takes different place on different mobile resolution…

Thanks before for any solution given here…

First of all:

Screen.width-(Screen.width/4*3))/2 = Screen.width *0.125

Screen.height-(Screen.height/4*3))/2 = Screen.height * 0.125

Screen.width/43 = Screen.width0.75

Screen.height/43 = Screen.height0.75

#pragma strict

var background1 : Texture;
var btn_next : Texture;

//background image dot start rect point
var backX : float;
var backY : float;

//background image size
var backWidth : float;
var backHeight : float;

//button image dot start rect point
var buttonX : float;
var buttonY : float;

//button image size
var buttonWidth : float;
var buttonHeight : float;

function OnGUI(){

	backX = Screen.width *0.125;
	backY = Screen.height * 0.125;
	backWidth = Screen.width*0.75;
	backHeight = Screen.height*0.75;
	buttonWidth = Screen.width*0.06;
	buttonHeight = Screen.height*0.05;
	buttonX = Screen.width *0.875 - Screen.width*0.06; //(backX + backWidth)- buttonWidth
	buttonY = Screen.height *0.875 - Screen.height*0.05; //(backY + backHeight)- buttonHeight

    GUI.DrawTexture(Rect(backX,backY,backWidth, backHeight),background1);
     //btn_next now it is at right-lower corner of whiteboard !!!

another option if you have more than one buttons is to use GUI.BeginGroup