C code for ATM TRANSACTIONS........

/*Author-Neelkant.S.patil,GMIT,Davangere*/

 /*Note Pin code is 7890*/

#include<stdio.h>
#include<conio.h>
unsigned long amount=1000,deposit,withdraw;
int choice,pin,k;
char another='y';


void main()
{
textbackground(1);


while(pin!=7890)
{
clrscr();
gotoxy(30,25);
printf("ENTER PIN:");
scanf("%d",&pin);
if(pin!=7890)
printf("PLEASE ENTER VALID PASSWORD\n");


}
clrscr();
do
{
printf("********Welcome to ATM Service**************\n");
printf("1. Check Balance\n");
printf("2. Withdraw Cash\n");
printf("3. Deposit Cash\n");
printf("4. Quit\n");
printf("******************?**************************?*\n\n");
printf("Enter your choice: ");
scanf("%d",&choice);
switch(choice)
{
case 1:
printf("\nYOUR BALANCE IN Rs : %lu ",amount);
break;
case 2:
printf("\nENTER THE AMOUNT TO WITHDRAW: ");
scanf("%lu",&withdraw);
if(withdraw%100!=0)
{
printf("\nPLEASE ENTER THE AMOUNT IN MULTIPLES OF 100");
}
else if(withdraw>(amount-500))
{
printf("\nINSUFFICENT BALANCE");
}
else
{
amount=amount-withdraw;
printf("\n\nPLEASE COLLECT UR CASH");
printf("\nYOUR CURRENT BALANCE IS%lu",amount);
}
break;
case 3:
printf("\nENTER THE AMOUNT TO DEPOSIT");
scanf("%lu",&deposit);
amount=amount+deposit;
printf("YOUR BALANCE IS %lu",amount);
break;
case 4:
printf("\nTHANK U USING ATM");
break;
default:
printf("\nINVALID CHOICE");
}
printf("\n\n\nDO U WISH TO HAVE ANOTHER TRANSCATION?(y/n): ");
fflush(stdin);
scanf("%c",&another);
if(another=='n'||another=='N')
k=1;
}while(!k);
printf("\n\nTHANX FOR USING NEELKANT`s BANK");
getch();


}