program in C++ to create a linked list

A program in C++ to create a  linked list  with insert_front and delete_front as member functions by creating to objects. Use constructor to initialize the objects.

#include<iostream.h>

#include<conio.h>

struct node

{int info;

 struct node *next;

};

typedef struct node node;

class Linklist

{

private:node *first;

 public:void insert_front();

            void delete_front();

            void display();

            Linklist()

            {first=NULL;

            }

};

void main()

{int a;

 clrscr();

 Linklist obj;

 while (a!=4)

 {clrscr();

  cout<<"\n  1.INSERT IN FRONT\n  2.DELETE FROM FRONT\n  3.DISPLAY LINKLIST\n  4.EXIT\n";

  cout<<"\n  ENTER THE CHOICE:";

  cin>>a;

  switch(a)

  {case 1:obj.insert_front();

              break;

   case 2:obj.delete_front();

              break;

   case 3:obj.display();

              break;

   case 4:cout<<"\n thanks for using the program";

              getch();

              break;

   default:cout<<"\n sorry you have entered wrong choice enter again:";

               getch();

  };

  getch();

 }

}

void Linklist::insert_front()

{node *temp;

 temp=new(node);

 if(temp==0)

 {cout<<"\n  MEMORY OVERFLOW";

  return;

 }

 cout<<"\n  ENTER THE NUMBER AT THE NODE:";

 cin>>temp->info;

 if(first==NULL)

 {first=temp;

  temp->next=NULL;

  return;

 }

 temp->next=first;

 first=temp;

}

void Linklist::delete_front()

{node *ptr;

 if (first==NULL)

 {cout<<"\n  UNDERFLOW";

 }

 else

 {ptr=first;

  first=first->next;

  cout<<"\n"<<"\t\t"<<ptr->info<<" DELETED";

  delete ptr;

 }

}

void Linklist::display()

{node *ptr;

 ptr=first;

 while(ptr!=NULL)

 {cout<<"\n"<<"\t\t"<<ptr->info;

  cout<<endl;

  ptr=ptr->next;

 }

}