If i uncomment the lines in between, all the records get deleted. Why??
void Hatao()
{
int no;
system("cls");
cout<<"\n\n\n\tDelete Record";
top:cout<<"\n\nPlease Enter The roll number of student You Want To Delete: ";
cin>>no;
fp.open("student.dat",ios::in|ios::ate);
fp.seekp(0,ios::beg);
fp.seekg(0,ios::beg);
fstream fp2;
fp2.open("Temp.dat",ios::out);
//int flag=0;
//if (st.retrollno()==no)
//flag=1;
//if (flag==0)
//{
// cout<<"\nRecord does not exist!!";
// char choice;
// cout<<"\nDo you want to enter another Roll no.??(y/n): ";
// cin>>choice;
// if((choice=='y')||(choice=='Y'))
// {
// system("cls");
// fp2.close();
// fp.close();
// goto top;
// }
// else
// {
// fp2.close();
// fp.close();
// goto bot;
// }
//}
while(fp.read((char*)&st,sizeof(student)))
{
if(st.retrollno()!=no)
{
fp2.write((char*)&st,sizeof(student));
}
}
fp2.close();
fp.close();
remove("student.dat");
rename("Temp.dat","student.dat");
cout<<"\n\n\tRecord Deleted ..";
bot:cout<<"\n\n\tPress <ENTER> to continue...";
cin.get(); cin.get();
}