13和21行出错，请问怎么改正？

Question

#include
using namespace std;
class CLIENT
{
public:
CLIENT(char name,int num)
{
ServerName=name;
ClientNum=num;
}
~CLIENT() {}
void showServerName() {cout<<"服务器名称为:"<<'name'<<endl;}
void showClientNum() {cout<<"已定义的客户数量为:"<<num<<endl;}
void showChangeServerName();
private:
static char ServerName;
static int ClientNum;
};
void showChangeServerName(char Cname)
{
ChangeServerName=Cname;
cout<<"服务器名称改变为:"<<'name'<<endl;
}
char ServerName='I';
int ClientNum=7;
void main()
{
CLIENT n();
n.showClientNum();
CLIENT c();
c.showChangeServerName();
}

Answer 1

 #include<iostream>
using namespace std;
class CLIENT
{
public:
    CLIENT(char name,int num)
    {
        ServerName=name;
        ClientNum=num;
    }
    ~CLIENT() {}
    void showServerName() {cout<<"服务器名称为:"<<ServerName<<endl;}
    void showClientNum() {cout<<"已定义的客户数量为:"<<ClientNum<<endl;}
    void showChangeServerName(char Cname);
private:
    static char ServerName;
    static int ClientNum;
};
void CLIENT::showChangeServerName(char Cname)
{
    ServerName=Cname;
    cout<<"服务器名称改变为:"<<Cname<<endl;
}

int main()
{
    CLIENT n('I', 7);
    n.showClientNum();
    CLIENT c('I', 7);
    c.showChangeServerName('A');
}