为何在VS2005中编译会出现 missing ';' before 'using'

//jk.h
#include<string>
using namespace std;
class student
{
private:
    int id;
    int age;
    string name;
public:
    student(int,int,string);
    void print(int,int,string);
}
//实现模块
#include<iostream>
#include<string>
#include"jk.h"
using namespace std;
void student::print(int a,int b,string s)
{
    cout<<a<<"  "<<b<<"  "<<s<<endl;
}
void student::student(int a,int b,string s)
{
    id=a;
    age=b;
    name=s;
}
//主程序

#include<iostream>
#include<string>
#include"jk.h"
using namespace std;
int main()
{
    int a,b;
    string s;
    cin>>a>>b>>s;
    student stu(a,b,s);
    stu.print(a,b,s);
    system("pause");
    return 0;
}
为何在VS2005中编译会出现 missing ';' before 'using'？？？