求解惑为什么在vc6.0中提示不能打开'iostream.h'

#include<iostream.h>
#include<string.h>


int main()
{
     string name;
     cout<<"请输入你的姓名：";
     cin>>name;
     cout<<"\nHello,"<<name<<endl;

     const int max=20;
     cout<<"max="<<max<<endl;

     return 0;
}
哪位大写帮我看看，为什么在vc6.0中总是报错
fatal error C1083: Cannot open include file: 'iostream.h': No such file or directory
执行 cl.exe 时出错.