代码出错，求大神解答
using UnityEngine;
using System.Collections;

public class cubeScript : MonoBehaviour {

// Use this for initialization
void Start () {


}

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


}
void OnGUI()
{

if (GUI.Button(new Rect(440, Screen.height - 25, 65, 23), "Snapshot"))
{
LoadHelp.UploadPNG(this, "Snapshot", delegate(bool result)
{
if (result)
{
Application.Externaleval_r("alert('ok')");
}
}
);
}
}
}
他说我有错错在 LoadHelp.UploadPNG(this, "Snapshot", delegate(bool result)这行
然后显示是这样的错误Assets/DressingroomExample/cubeScript.cs(22,10): error CS0103: The name `LoadHelp' does not exist in the current context
这是什么问题？

[解决办法]
找不到LoadHelp类，确保是否加入了该类的命名空间引用
[解决办法]
LoadHelp在哪里定义的
添加引用了么