高手帮看看C++一个程序 哪错了...

#include <iostream>
using namespace std;
class string
{
private:
    char *str;
    int len;
public:
    void showstr()
    {cout<<"string:"<<str<<",length:"<<len<<endl;}
    string()
    {len=0;
    str=null;}
    string(char *p)
    {len=strlen(p);
    str=new char[len+1];
    strcpy(str,p);
    }
    ~string()
    {
        if(str!=null)
        {delete [] str;
        str=null;
        cout<<"析构函数被调用"<<endl;
        }
    }
    void main(void)
    {
        char s[]="ABCDE";
        string s1(s);
        string s2("123456");
        s1.showstr();
        s2.showstr();}
运行的时候出现这个错误 fatal error C1004: unexpected end of file found