deepak_kr_mehta

hello sir
sir when i run this following programme it will showing me error.plz assist me to remove it

#include<iostream.h>
#include<conio.h>
class student
{
int id;
mutable int j;//it will showing error 1. declaration missing //2. undefined symbol hpublic:
void set(int i)
{
id=i;
j=90;// cannot modify}
void print()
{
cout<<id<<j;
}
};
void main()
{
student s1;
s1.set(5);
s1.print();
}

sir after place mutable it will showing me same error with extra syntex error.
plz sir correct it.
thanx
from
deepak kr.