box *p=new box1 ； 错了吗？请教……

#include<iostream>
using namespace std;
class  box
{
       public:
       box(int x,int y,int z)
       {
               chang=x;
               kuan=y;
               gao=z;
       }
       virtual void show ()
       {
            cout<<chang<<"  "<<kuan<<"  "<<gao<<endl;
       }
       virtual ~box()
       {
             cout<<"基类清理"<<endl;
       }      
      
       protected:
       int chang;
       int kuan;
       int gao;
};
class box1:public box
{
      public:
      box1(int x,int y,int z,int u):box(x,y,z)
      {
            color=u;
      }
      virtual void show()
      {
           cout<<chang<<"  "<<kuan<<"  "<<gao<<"  "<<color<<endl;
      }
      virtual ~box1()
      {
              cout<<"派生类清理"<<endl;
      }        
      protected:
      int color;
};

int main()
{
    box *p=new box1;  //提示这里错了         
    delete p;
    system("pause");
    return(0);
}