这个问题怎么解决，求解

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

class Employee
{
public:
	Employee(string na,int bm);
	string getname();
	virtual float getSalary(int month)=0;
protected:
	string name;
	int brith_month;

};


Employee::Employee(string na,int bm):name(na),birth_month(bm){}
string Employee::getname(){return name;}

int main()
{
	return 0;
}

Eerror C2614: 'Employee' : illegal member initialization: 'birth_month' is not a base or member
 这个问题怎么解决

问题见注释处，brith_month  <===>  birth_month

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

class Employee
{
public:
	Employee(string na,int bm);
	string getname();
	virtual float getSalary(int month)=0;
protected:
	string name;
	int brith_month;
};
Employee::Employee(string na,int bm):name(na),brith_month(bm){}//birth_month(bm){}
string Employee::getname(){return name;}
int main()
{
    
	return 0;
}