C++ Telephone Directory System

#include <iostream>
#include <conio.h>
#include <stdio.h>
#include <math.h>
using namespace std;
class smart_phone
{
private:
string phone_number; 
string message;
string credit;
string inbox;
public:
void no_bloking();
void speed_dail();
void emergency_no();
//Getters and Setters.
string GetPhone_number()
{
return phone_number;
}
void SetPhone_number(string pn)
{ 
phone_number=pn;
}
string GetCredit()
{
return credit;
}
void SetCredit(string pn)
{
credit=pn;
}
string GetMessage()
{
return message;
}
void SetMessage(string msg)
{
message=msg;
}
}; // Class end.
// Main body start.
int main ()
{
smart_phone n1;
string a,b,c,d;
cout<<"wellcome to phone directory:\n\n";
cout<<"enter mobile number : \n";
cin>>a;
n1.SetPhone_number(a); 
//cout<<"enter yor credit : \n";
//cin>>c;
//n1.SetCredit(c);
cout<<"print msg:\n";
cin>>d;
n1.SetMessage(d);
cout<<"\n\n\n========================\nOverview of your provide information:\n\n"; 
cout<<"Your Mobile number : "<<n1.GetPhone_number()<<endl;
// cout<<"your Balance : "<<n1.GetCredit()<<endl;
cout<<"your msg is : "<<n1.GetMessage()<<endl;
getch();
}