String 导入什么以在actionscript上使用字符串类型？

我对actionscript一窍不通，从来没有使用过它，但我编译了一个Unity项目来flash，为了进行浏览器javascript通信，我打算在.as代码上提供一个类。。 unity正在使用它不知道类型字符串： “找不到类型或类型不是编译时常量：string。”

这是我的代码，请注意，我甚至没有flash编译器，我使用的是notepad++，所以我处于雷区，不懂语言，无法调试它

import flash.external.ExternalInterface;
import flash.system.Security;

import global.SCORMInsideActionScriptFunctions;

public class BrowserCommunicator
{
    public static function callFromJavascript() : void
    {
        trace("Javascript successfully called ActionScript function.");
    }

    // callback to register:
    public static function GetSessionTime() : string
    {
        return SCORMInsideActionScriptFunctions.GetSessionTime()
    }


    //Sets up an ExternalInterface callback and calls a Javascript function.
    public static function TestCommunication() : void
    {
        if (ExternalInterface.available)
        {
            try
            {
                ExternalInterface.addCallback("callFromJavascript", callFromJavascript);

                // mine:
                ExternalInterface.addCallback("GetSessionTime", GetSessionTime);


            }
            catch (error:SecurityError)
            {
                trace("A SecurityError occurred: " + error.message);
            }
            catch (error:Error)
            {
                trace("An Error occurred: " + error.message);
            }

            ExternalInterface.call('calledFromActionScript');
        }
        else
        {
            trace("External interface not available");
        }
    }

    public static function FlushData_ServerToCache() : void
    {
        if (ExternalInterface.available)
        {
            // calls the java function here:
            ExternalInterface.call('flushData');
        }
        else
        {
            trace("External interface not available");
        }
    }

    public static function SubmitData_CacheToServer() : void
    {
        if (ExternalInterface.available)
        {
            ExternalInterface.call('submitData');
        }
        else
        {
            trace("External interface not available");
        }
    }

    public static function SetData_AppToCache( field : string, data : string) : void
    {
        if (ExternalInterface.available)
        {
            ExternalInterface.call('setData', field, data);
        }
        else
        {
            trace("External interface not available");
        }
    }

    public static function GetData_CacheToApp( field : string ) : string
    {
        if (ExternalInterface.available)
        {
            return ExternalInterface.call('getData', field);
        }
        else
        {
            trace("External interface not available");
            return "";
        }
    }
}

---

}

只写字符串而不是字符串：）

你一定在开玩笑吧=\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu嘿，记事本++正在给我的数据着色：字符串变量，它是保留。它是被着色的数据词..我是说