请教关于cout和printf的一个问题~

#include <iostream>
#include <windows.h>
using namespace std;

int main(int argc, char* argv[])
{
    int nSelect=::MessageBox(NULL,"Hello,Windows XP","Greetings",MB_OKCANCEL);
    if(nSelect==IDOK)
        cout<<"用户选择了“确定”按钮<<endl;
    else
        cout<<"用户选择了“取消”按钮<<endl;
    return 0;
}

#include "stdafx.h"
#include <windows.h>

int main(int argc, char* argv[])
{
    int nSelect=::MessageBox(NULL,"Hello,Windows XP","Greetings",MB_OKCANCEL);
    if(nSelect==IDOK)
         printf("用户选择了“确定”按钮\n");
    else
             printf("用户选择了“取消”按钮\n");
    return 0;
}

error C2001: newline in constant
error C2143: syntax error : missing ';' before 'else'
error C2001: newline in constant
error C2143: syntax error : missing ';' before 'return'