Showroom Database System - Project

This Programme is basically a Showroom database base in which Entry of he car owners,cars,customers are stored in files and can be retrieved.

#include<stdlib.h>
#include<string.h>

void owner_entry(void);
void owner_read(long);
void car_entry(void);
void car_read(void);
long customer_entry(void);
void customer_read(void);
void car_match(int);
void customer_match(long);
void my_logo(void);

void main(void)
{
int choice;char ch[1];int i=2,flag=1;
long demand;
int gd=DETECT ,gm;
initgraph(&gd,&gm,"c:\tc\bgi");
my_logo();
setbkcolor(1);
A:
cleardevice();
setfillstyle(i,9);
floodfill(1,1,1);
settextstyle(5,0,4);
outtextxy(0,0,"ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ");
outtextxy(0,30,"ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄMAIN MENUÄÄÄÄÄÄÄÄÄÄÄÄÄÄ");
outtextxy(0,60,"ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ");
outtextxy(0,90,"1. New Owner Entry with his car specification.");
outtextxy(0,120,"2. New Customer Entry.");
outtextxy(0,150,"3. View all available cars.");
outtextxy(0,180,"4. View all customers.");
outtextxy(0,210,"5. Exit.");
outtextxy(0,240,"ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ");
outtextxy(0,270,"Enter your choice(1-5) : ");
outtextxy(0,300,"ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ");
ch[0]=getch();
ch[1]='