unity3d中实现聊天功能

using UnityEngine;
using System.Collections;
public class Chat : MonoBehaviour {
        bool usingChat = false;
    bool showChat = false;
    string inputField = "";
    Vector2 scrollposition;
    int width = 500;
    int height = 200;
    string playerName;
    float lastUnfocusTime = 0;
    Rect window;
    ArrayList }