全局运算符重载问题

// resign5.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <iostream.h>
//******************************
CUser operator + (int nData,CUser &refUser)      //声明全局函数 + 重载
{
    CUser eUser;
    eUser.m_nLevel = refUser.m_nLevel + nData;
    reuturn eUser;
}
//******************************
class CUser
{
private:
    int m_nLevel;
public:
    //--------------------------------------- 构造函数
    CUser()
    {
        m_nLevel = 1;
    }
    //--------------------------------------- +重载
    CUser operator + (CUser &redoUser)
    {
        CUser aUser;
        aUser.m_nLevel = m_nLevel + redoUser.m_nLevel;
        return aUser;
    }
    //--------------------------------------- 读取操作员等级
    int GetLevel()  const
    {
        return this->m_nLevel;
    }
    //---------------------------------------
    CUser operator + (int nData)
    {
        CUser dUser;
        dUser.m_nLevel = m_nLevel + nData;
        return dUser;
    }
    //---------------------------------------声明友元函数 +重载
    friend CUser operator + (int nData,CUser &refUser);

};
int main(int argc, char* argv[])
{
    //--------------------------------------
    CUser Usera,Userb;
    CUser Userc = Usera + Userb;
    cout<<Userc.GetLevel()<<endl;
    //--------------------------------------
    CUser Userd;
    CUser Userf = Userd + 10;
    cout<<Userf.GetLevel()<<endl;
    //--------------------------------------
    CUser Usere;
    CUser Userg = 10 + Usere;
    cout<<Userg.GetLevel()<<endl;
    return 0;
}