Page 403 - C++

cin>>clas;
cout<<"\n\n\t Enter The Section Of The Student : ";
cin>>section;
section=toupper(section);
fstream file ,file2,file3,file4;
file.open("fee.dat", ios::in|ios::binary);

int flag=0;

while(file.read((char *)&s, sizeof(s)))
{
if(s.cls==clas)
{
flag=1;
break;
}

}
if (flag==0)
{
cout<<"\n\t Please check the the input for class.......";
getch();
file.close();
return;
}

file2.open("student.dat", ios::in|ios::binary);
flag=0;
while(file2.read((char *)&s, sizeof(s)))
{
if(s.retno()==anum)
{
flag=1;
break;
}
}
if (flag==0)
{
cout<<"\n\n\t Please check the Admission no........";
getch();
file.close();
file2.close();
return;
}
long offset=0;
file3.open("Sfee.dat",ios::in|ios::out|ios::binary);
cout<<"\n\t Enter term : ";
cin>>t;
flag=0;
while(file3.read((char *)&sf,sizeof(sf)))
{
if (sf.retad()==anum && sf.retterm()==t)
{
flag=1;