Unity C#

using UnityEngine;
using System.Collections;

public class Login : MonoBehaviour {

    public Texture LoginBackground;
    public Texture2D stylebackground;
    public GUIStyle LoginStyle;
    public GUIStyle LoginTextBox;
    public GUIStyle LoginButton;
    public string Username;
    public string Password;
    public float transparent;
    private string url;
    public WWW w;
    public WWWForm loginform;
    // Use this for initialization
    void Start () {
        LoginStyle.fontSize = 72;
        LoginStyle.alignment = TextAnchor.MiddleCenter;
        LoginTextBox.fontSize = 20;
        LoginTextBox.alignment = TextAnchor.MiddleCenter;
        LoginTextBox.normal.background = stylebackground;
        LoginButton.fontSize = 30;
        LoginButton.alignment = TextAnchor.MiddleCenter;
        url = "http://redlightlife.tk/scripts/checklogin.php";
        loginform = new WWWForm();
    }

    // Update is called once per frame
    void Update () {

    }

    void OnGUI() {
        GUI.backgroundColor = Color.black;
        GUI.DrawTexture(new Rect(0,0,Screen.width,Screen.height),LoginBackground,ScaleMode.StretchToFill, false, 0.0f);
        GUI.Label(new Rect(Screen.width/2-250,Screen.height/2-250,500,250),"Username:", LoginStyle);
        Username = GUI.TextField(new Rect(Screen.width/2-250,Screen.height/2-80,500,50), Username, 10, LoginTextBox);
        GUI.Label(new Rect(Screen.width/2-250,Screen.height/2-50,500,250),"Password:", LoginStyle);
        Password = GUI.TextField(new Rect(Screen.width/2-250,Screen.height/2+120,500,50), Password, 10, LoginTextBox);
        if (GUI.Button(new Rect(Screen.width/2-150,Screen.height/2+200,300,50),"Login:", LoginButton))
        {
            //CheckLogin();
            StartCoroutine(CheckLogin());
        }
    }

    IEnumerator CheckLogin()
    {
            loginform.AddField("username", Username);
            loginform.AddField("password", Password);
            w = new WWW(url,loginform);
            yield return w;
            Debug.Log("Downloaded");
            if (w.error != null)
            {
            print(w.error);
            }
            if (w.error == null)
            {
            print("Fetching Data");
            print("Uwsername=" + Username);
            print ("Passowrd=" + Password);
            string formText = w.text;
            w.Dispose();
            print(formText);
            }
    }
}