this is my college project I am sharing i want to add a log in feature in this... please help me out

tejas.cpp

#include<graphics.h>
#include<fstream.h>
#include<conio.h>
#include<process.h>
#include<stdio.h>
#include<string.h>
class student
{
char fname[15],mname[15];     //father name & mother name
int rollno,admin_no,dd,mm,yy;    //roll number,Admission no, date,Month,Year
public:
char name[15];
void getdata();               //function for input data
void putdata();
void modifydata();           //Function to edit data
void display();              //Function to display data
int get_roll()            //function return rollno
{ return rollno; }
}  s1;
void student::getdata()
{ clrscr();
gotoxy(10,2);textcolor(0);textbackground(10);
cprintf(" ::  RECORD ENTRY SECTION  ::");
gotoxy(12,6);textcolor(3);textbackground(0);
cprintf("1. Enter the rollno :");cin>>rollno;
gotoxy(12,7);textcolor(3);
cprintf("2. Enter the name :");gets(name);
gotoxy(12,8);textcolor(3);
cprintf("3. Father name  :");gets(fname);
gotoxy(12,9);textcolor(3);
cprintf("4. Mother name  :"); gets(mname);
gotoxy(12,10);textcolor(3);
cprintf("5. Enter Admission no. :");cin>>admin_no;
gotoxy(12,11);textcolor(3);
cprintf("6. Enter date of birth :");
gotoxy(14,12);textcolor(3);
cprintf("   Date:");cin>>dd;
gotoxy(14,13);textcolor(3);
cprintf("   Month:");cin>>mm;
gotoxy(14,14);textcolor(3);
cprintf("   Year :");cin>>yy; }

void student::putdata()
{
clrscr();
gotoxy(10,2);textcolor(1);textbackground(10);
cprintf(" ::  RECORD  ::");
gotoxy(12,6);textcolor(3);textbackground(0);
cprintf("1. Rollno : ");cout<<rollno;
gotoxy(12,7);textcolor(3);
cprintf("2. Name : ");puts(name);
gotoxy(12,8);textcolor(3);
cprintf("3. Father name : ");puts(fname);
gotoxy(12,9);textcolor(3);
cprintf("4. Mother name : "); puts(mname);
gotoxy(12,10);textcolor(3);
cprintf("5. Admission no.: ");cout<<admin_no;
gotoxy(12,11);textcolor(3);
cprintf("6. Date of birth: ");cout<<dd<<"/"<<mm<<"/"<<yy;
}
void student::modifydata()
{ char nm[15],fath[15],moth[15];
int rno,d,m,y,admis;
clrscr();
gotoxy(10,2);textcolor(0+BLINK); textbackground(8);
cprintf(" Enter new record :");
gotoxy(11,5);textcolor(14); textbackground(0);
cprintf("  Name :");gets(nm);
gotoxy(11,6);textcolor(14);
cprintf(" Roll No. :");cin>>rno;
gotoxy(11,7);textcolor(14);
cprintf(" Father name :");gets(fath);
gotoxy(11,8);textcolor(14);
cprintf(" Mother name :");gets(moth);
gotoxy(11,9);textcolor(14);
cprintf(" Admission ID :");cin>> admis;
gotoxy(11,10);textcolor(14);
cprintf(" Date of Birth :");
gotoxy(11,11);textcolor(14);
cprintf(" Date :"); cin>>d;
gotoxy(11,12);textcolor(14);
cprintf(" Month :");  cin>>m;
gotoxy(11,13);textcolor(14);
cprintf(" Year :"); cin>>y;
strcpy(name,nm);
strcpy(fname,fath);
strcpy(mname,moth);
rollno=rno;
admin_no=admis;dd=d;mm=m;yy=y;
}
void student::display()
{ student *p3;
int z=6;
clrscr();
gotoxy(30,1);
textbackground(1);textcolor(6);
cprintf("Student Information");
gotoxy(23,2);textbackground(RED);
textcolor(WHITE+BLINK);
cprintf("::Display Record::") ;
textbackground(0);textcolor(11);
gotoxy(1,3);
cprintf("--------------------------------------------------------------------------");
gotoxy(1,4);
cprintf(" Name     Rollno   Admission no.   DateofBirth    Fathername      Mothername  ");
gotoxy(1,5);
cprintf("---------------------------------------------------------------------------  ");
textcolor(7);
ifstream fff;
fff.open("student.txt",ios::in);
while(!fff.eof())
{
fff.read((char*)&s1,sizeof(s1));
{
gotoxy(1,z);
cout<<name;
gotoxy(14,z);
cout<<rollno;
gotoxy(23,z);
cout<<admin_no;
gotoxy(36,z);
cout<<dd<<"/"<<mm<<"/"<<yy;
gotoxy(54,z);
puts(fname);
gotoxy(70,z);
puts(mname);
z++;
}}
//fff.fclose();
gotoxy(55,24);
textcolor(13);
cprintf("Press Any Key  to Continue");
getch();
}
int main()
{

  int gd=DETECT,gm;
clrscr();
initgraph(&gd,&gm,"c:\\tc\\bgi");
	 setcolor(9);
	 settextstyle(5,0,8);
	outtextxy(0,50,"A PROJECT ON");
	 settextstyle(8,0,3);
	 setcolor(10);
	outtextxy(90,200,"STUDENT DATABASE MANAGEMENT");
	setcolor(12);
	outtextxy(210,270,"APPLICATION");
	settextstyle(3,0,3);
	setcolor(4);
	outtextxy(210,370,"Prepared By:");
	setcolor(5);
	outtextxy(160,400,"Tejas, Satish & Naman");


	getch();
	closegraph();




	clrscr();
	initgraph(&gd,&gm,"c:\\tc\\bgi");

	setcolor(3);
	settextstyle(1,0,1);
	outtextxy(250,300,"WELCOME");

	getch();
	closegraph();




start1:
start:
clrscr();
int a;
textcolor(5 + BLINK);
textbackground(7);

gotoxy(18,2);
cprintf("   ::  STUDENT INFORMATION DATABASE RECORDER ::");
gotoxy(10,4); textcolor(12); textbackground(0);
cprintf("   1.  Enter new record");
gotoxy(10,6); textcolor(12);
cprintf("   2.  Search student record");
gotoxy(10,8); textcolor(12);
cprintf("   3.  Display record");
gotoxy(10,10); textcolor(12);
cprintf("   4.  Modify the record");
gotoxy(10,12); textcolor(12);
cprintf("   5.  Delete student record");
gotoxy(10,14); textcolor(12);
cprintf("   6.  Exit");
gotoxy(31,16); textcolor(2);

cprintf("Enter the option:" );cin>>a;
do{
switch(a)
{
case 1:     clrscr();
		 char ch;
		 ofstream fout;
		 fout.open("student.txt",ios::app|ios::ate);
		 if(!fout)
		 {
		 cout<<"File not exist ";
		 exit(1);}
		 do{
		 s1.getdata();
		 fout.write((char*)&s1,sizeof(s1));
		clrscr();
		  gotoxy(10,7);textcolor(4);
		 cprintf("  --- Record Added Successfully ----");
		 gotoxy(10,8);textcolor(3);
		 cprintf("Do u want to add more record(y/n)\t");cin>>ch;
		}while(ch=='y'||ch=='Y');
		 fout.close();
		 goto  start;

case 2:     start3:
		 clrscr();
		  int a; gotoxy(10,2);textcolor(10+BLINK);
			 cprintf("   ::  Search Record :: " );
			 gotoxy(11,6);textcolor(14);
			 cprintf(" 1. Search  by roll no.");
			 gotoxy(11,7);textcolor(14);
			 cprintf(" 2. Search by name ");
			 gotoxy(11,8);textcolor(14);
			 cprintf(" 3. Back");
			 gotoxy(17,9);textcolor(6);
			 cprintf(" Enter the option :");cin>>a;
			 switch(a)
			 {
			 case 1:  clrscr();
			 int r_no;
			 char found='n';
			 gotoxy(17,17); textcolor(14);
			 cprintf("Enter the rollno :");cin>>r_no;
		  ifstream fin;
		  fin.open("student.txt",ios::in);
		  while(!fin.eof())
		  {
		  fin.read((char*)&s1,sizeof(s1));
		  if(s1.get_roll() == r_no)
		  { s1.putdata();
			 found='y';
			 getch();
			//  goto start3;
			 }  else
		  if(found=='n')
		  {
		  clrscr(); gotoxy(25,25);textcolor(9);
		  cprintf(" Sorry! record not found");
		  getch(); }  }
		  fin.close();
		  goto start3;
			 case 2:  clrscr();
		student *s;
		s=&s1;
			 char s_name[15];
			 char confirm='n';
			 gotoxy(17,17); textcolor(14);
			 cprintf("Enter the name :");gets(s_name);
		  ifstream fn;
		  fin.open("student.txt",ios::in);
		  while(!fn.eof())
		  {
		  fn.read((char*)&s1,sizeof(s1));
		  if(strcmpi(s_name ,s->name)==0)
		  { s->putdata();
			 confirm='y';
			 getch();
			  goto start3;
			 } }
		  if(confirm=='n')
		  {
		  clrscr(); gotoxy(25,25);textcolor(9);
		  cprintf(" Sorry! record not found");
		  getch();
		  }
		  fn.close();
		  getch();
		  goto start3;

			 case 3:
			 goto start;
			 default:   gotoxy(15,10);textcolor(4);
			 cprintf("Illegal option");
			 break;
			 }

		break;
case 3:     clrscr();
			  s1.display();
		 break;
case 4:   clrscr();
		char find='n';
		int r_n;
		long pos;
		  fstream ff;
		  ff.open("student.txt",ios::in|ios::out|ios::binary);
		  gotoxy(15,15);textcolor(5);
		  cprintf("Enter the rollno to modify");
		  cin>>r_n;
		  while(!ff.eof())
		  {pos=ff.tellg();
		  ff.read((char*)&s1,sizeof(s1));
		if(s1.get_roll()==r_n)
		{ find='y';
		 s1.modifydata();
		ff.seekg(pos);
	  ff.write((char*)&s1,sizeof(s1));
	  ff.close();
	  goto start; } }

		if(find=='n')
		{  clrscr();gotoxy(15,15);textcolor(3);
		cprintf("Record not found");
		}
		break;
case 5:    clrscr();
	 student *ss;
	 ss=&s1;
		int stno;        //for rollno
		char found ='f',confirm='n';
		ifstream fi;
		fi.open("student.txt",ios::in);
		ofstream fo;
		fo.open("tem.txt",ios::out);
		cout<<"Enter the rollno to delete:";cin>>stno;
		while((!fi.read((char*)&s1,sizeof(s1))))
		{
		if(ss->get_roll()==stno)
		{
		ss->putdata();
		found='y';
		cprintf("Are you sure (y/n) :");cin>>confirm;
		if(confirm=='n'||confirm=='N')
		{
		fo.write((char*)&s1,sizeof(s1));
		cprintf("Abort by the user");
		getch();  }
		else
		fo.write((char*)&s1,sizeof(s1));
		}    }
		if(found=='f')
		{
		cprintf("Record not found ");
		}
		fi.close();
		fo.close();
		remove("student.txt");
		rename("tem.txt","student.txt");
		goto start;
case 6:    clrscr();
		gotoxy(20,6); textcolor(12); textbackground(0);
		cprintf("Thanks For Using our Program!... Bye");
		gotoxy(23,12); textcolor(20); textbackground(0);
		cprintf("By Tejas, Satish & Naman, BPIBS");
		/*setcolor(9);
		settextstyle(7,0,1);
		outtextxy(10,50,"By Tejas, Satish & Naman, BPIBS");*/
		getch();
		exit(0);
		break;
default: textcolor(1+BLINK);
	  gotoxy(10,20);
		 //	 clrscr();
		cprintf(" !!! Wrong choice  !!! ");// break;
		getch();goto start;

}}  while(0);
getch();
return 0;
}

LOL I did this shit in my first year. I am so embarrassed about this project...