delete record from file

[bitbyte89]

void delData()
{
int id;

fstream delData("Depart ment1.txt",ios: :out | ios::in|ios::bi nary);
if(!delData)
{
cerr<<"file could not be opened"<<"\n";
}
else
{
cout<<" Enter the ID of department you want to modify :"<<"\n";
cin>>id;

Department d;

delData.seekg(( id-1)*sizeof(Depar tment));

delData.read((c har*)(&d),sizeo f(Department));

int iid=d.getID();
if(iid!=0)
{
Department d1;
delData.seekp(( id-1)*sizeof(Depar tment));

delData.write(( char*)(&d1),siz eof(Department) );


}
else
cout<<" Id "<<id<<" is already empty "<<"\n";
}
}


can any1 please help that this also is deleting perfectly the record but the record key that is the department id is printing like
1
2
4
5
it is deleting 3rd record but how can i get the sorted record??