有一个BUG错误 求各位帮帮吧？

/************************/
/*    example of 5.7    */
/************************/

#include<iostream>
#include<string>
using namespace std;


/*********************************************************/
/*               class of Employee                       */
/*********************************************************/
class Employee
{
protected:
 char *name;                //the number of employee
 int individualEmpNo;
 int grade;                  //work position
 float accumPay;
 static int employeeNo;      //The max number of compus emploayee number
public:
 Employee()
 {name=new char[];
 individualEmpNo=employeeNo++;
 cout<<"职工姓名:";
 cin>>name;
 accumPay=0.0; 
 }

 ~Employee()
 {
  cout<<"destructe employee class"<<endl;
 }
  virtual void pay()=0;
  //virtual void promote();             //the money of promote
  virtual void displayStatus();
};

/*********************************************************/
/*               class of Technician                     */
/*********************************************************/
class Technician:public Employee
{
private:
    float hourlyRate;          //the salary of a hour
 int workHours;             //work hour
public:
 Technician()
 {
 hourlyRate=100;
 cout<<name<<"本月工作时间:";
 cin>>workHours;
 }

 void pay()
 {
  accumPay=hourlyRate*workHours;
 }
 void displayStatus()
 {
 cout<<"兼职技术人员:"<<name<<",编号:";
 cout<<individualEmpNo<<",本月工资:"<<accumPay<<endl;
 }
};

/*********************************************************/
/*               class of Manager                        */
/*********************************************************/
class Manager:virtual public Employee
{
protected:
  float monthlyPay;

public:

 Manager()
 {
 monthlyPay=8000;
 }

  void pay()
  {
  accumPay=monthlyPay;
  }
  void displayStatus()
  {
  cout<<"经理:"<<name<<",编号:";
  cout<<individualEmpNo<<",本月工资:"<<accumPay<<endl;
  }

};

/*********************************************************/
/*               class of Salesman                       */
/*********************************************************/
class Salesman:virtual public Employee
{
protected:
  float commRate;
  float sales;      //salary of monthy
public:
 Salesman()
 {
 commRate=0.04f;
 cout<<name<<"本月销售额:";
 cin>>sales;
 }
 void pay()
 {
 accumPay=sales*commRate;
 }
 void display()
 {
 cout<<"销售员:"<<name<<",编号:";
 cout<<individualEmpNo<<",本月工资:"<<accumPay<<endl;
 }
};


/*********************************************************/
/*               class of Salesmanager                   */
/*********************************************************/
class Salesmanager:public Manager,public Salesman
{
   public:
   Salesmanager()
   {
   monthlyPay=5000;
   commRate=0.05f;
   cout<<name<<"所管部门月销售量:";
   cin>>sales;
   }
   void pay()
   { 
 
    accumPay=monthlyPay+commRate*sales;
   }

   void displayStatus()
   {
   cout<<"销售经理:"<<name<<",编号:"<<individualEmpNo<<":本月工资:"<<accumPay<<endl;
   }
};

int Employee::employeeNo=10000;

int main()
{
Manager m1;
Technician t1;
Salesman s1;
Salesmanager sm1;

Employee *em[4]={&m1,&t1,&s1,&sm1};
cout<<"上述人员的基本信息为:"<<endl;

for(int i=0;i<4;i++)
{
em[i]->pay();
em[i]->displayStatus();
}
return 0;
}

--------------------------------------------------------------------------
Linking...
SDFAs.obj : error LNK2001: unresolved external symbol "public: virtual void __thiscall Employee::displayStatus(void)" (?displayStatus@Employee@@UAEXXZ)
Debug/ddsaaA.exe : fatal error LNK1120: 1 unresolved externals
Error executing link.exe.

看着上面的错误提示 也不知道错在哪里？希望各位 能忙里偷闲 过来帮忙看看 小弟不胜感激。 一个BUG?求能人?帮帮忙吧？
[解决办法]
Manager m1;Technician t1;Salesman s1;Salesmanager sm1;
有的类里没有实现基类的虚函数
[解决办法]
基类Employee的displayStatus函数没有实现
这样：
void displayStatus() { }
[解决办法]
virtual void displayStatus();
改为
virtual void displayStatus(){};
试试