请问 system("pause"); 怎么用？

我是菜鸟,我写了个程序，结尾用了个system("pause"); 但是错的，请问这个语句怎么用？

#include <iostream.h>
main ()
{
    float a,b,c;
    char d;
    cout << "本程序只适合四则运算\n";
    cout << "只进行加减乘除运算\n";
    cin >> a >> d >>b;
   
    switch(d)
   { case '-': c=a-b;
              cout<< a <<"-"<< b << "=" << c <<endl;
              break;
     case '+': c=a+b;
              cout<<a <<"+"<< b << "="<< c <<endl;
              break;
     case '*': c=a*b;
              cout<<a <<"*"<< b << "="<< c <<endl;
              break;
     case '/': c=a/b;
              cout<<a <<"/"<< b << "="<< c <<endl;
              break;
     default: cout << "输入的不是四则运算\n" ;
   }
   system ("pause");
}