Small Program To Store Student Information In File In C++

#include<iostream.h>
#include<conio.h>
#include<iomanip.h>
#include<stdio.h>
#include<fstream.h>
#include<string.h>

class stu
{
   char roll[20],name[30];
 public:
   void getstu()
   {
    cout<<"\n\t Enter Roll and Name: ";
    cout<<"\n\t Roll: ";
    cin>>roll;
    cout<<"\n\t Name: ";
    gets(name);
   }
   void putstu()
   {
    cout<<"\n\t Details of Students";
    cout<<"\n"<<setw(15)<<roll;
    cout<<setw(25);
    puts(name);
   }
   void editstu()
   {
    cout<<"\n\t Roll No: "<<roll;;
    cout<<"\n\t Enter Roll and Name: ";
    cout<<"\n\t Roll: ";
    cin>>roll;
    cout<<"\n\t Name: ";
    gets(name);
   }
 void report()
 {cout<<roll<<setw(20)<<name;}
 char* retroll()
 {return roll;}
};
 /*************************************************************************
 /*******************************************************************/
 fstream f1,f2;
 stu s;
 //**********************************************************************
void getdata()
{
 char ch;
 f1.open("stu.dat",ios::out|ios::app);
 do
 {
  clrscr();
  s.getstu();
  f1.write((char *)&s,sizeof(s));
  cout<<"\n\t Do You want to add more record:\n";
  cin>>ch;
 }
 while(ch=='y'||ch=='Y');
 f1.close();
}

 void putdata()
 {
   clrscr();
   f1.open("stu.dat",ios::in);
   if(!f1)
   {
    cout<<"\n\t\t********* Records Are Empty*************\n";
    getch();
    return;
   }
   cout<<"\n====================STUDENT DETAILS==========================";
   cout<<"\n\t************************************************************";
   cout<<"\n\t Roll No."<<setw(20)<<"Name";
   while(f1.read((char *)&s,sizeof(s)));
   {s.report();}
   f1.close();
   cout<<"\n\t Press any key to go back:";
   getch();
 }
void putsdata()
{             char n[15];
 cout<<"\n\t Individual Student Details:\n";
 int flag=0;
f1.open("stu.dat",ios::in);
while(f1.read((char*)&s,sizeof(s)))
{
if((strcmpi(s.retroll(),n)==0))
{
s.putstu();
flag=1;
}
}

f1.close();
if(flag==0)
cout<<"\n\nStudent does not exist";
getch();
}
void main()
{
 clrscr();
 char ch;
 cout<<"\n\t\tMake Your Choice\n";
 cout<<"\nPress 1 for Add student:";
 cout<<"\nPress 2 for show all student details:";
 cout<<"\npress 3 for show individual student data: ";
 cout<<"\n\t press any option===> ";
 cin>>ch;
 switch(ch)
 {
  case '1': getdata(); break;
  case '2': putdata(); break;
  case '3': putsdata(); break;
  default: cout<<"poor choice:";
  getch();
 }
}