GUI draw two windows

I have created one window,I need to create one more window on the same scene.Here is the i have written for one window

void OnGUI()
	{
		GUI.Window (0, new Rect (100,200,450,300), LoginWindow, "Login and Registration system");

	}
	/* user interface*/

	void LoginWindow(int windowID)
	{
		GUI.Label (new Rect (140, 40, 130, 100), "Enter the Username");
		username = GUI.TextField (new Rect (25, 60, 375, 30), username);
		GUI.Label (new Rect (140, 92, 130, 100), "Enter the Password");
		password = GUI.TextField(new Rect (25, 115, 375, 30), password);
		if (GUI.Button (new Rect (29, 160, 175, 50), "Login"))
		StartCoroutine(handleLogin(username,password));
		GUI.Label (new Rect (55, 222, 250, 100),output);
		if(GUI.Button (new Rect (225, 160, 175, 50), "Register"))
			Application.LoadLevel ("Registration");
		//StartCoroutine(handleRegister(username,password));


	}

How to create one more window?

Just add another call to “GUI.Window”. First parameter (ID) should be 1.

Here you can find this example:

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    public Rect windowRect0 = new Rect(20, 20, 120, 50);
    public Rect windowRect1 = new Rect(20, 100, 120, 50);
    void OnGUI() {
        windowRect0 = GUI.Window(0, windowRect0, DoMyWindow, "My Window");
        windowRect1 = GUI.Window(1, windowRect1, DoMyWindow, "My Window");
    }
    void DoMyWindow(int windowID) {
        if (GUI.Button(new Rect(10, 20, 100, 20), "Hello World"))
            print("Got a click in window " + windowID);
        
        GUI.DragWindow(new Rect(0, 0, 10000, 10000));
    }
}