Log_in Portal.c

#include<stdio.h>
#include<malloc.h>
#include<stdlib.h>
typedef struct Data{
	char name[50];
	int admn,cia;
	char usn[20];
    }data;
	
void registration()
{	
	data *m,*c;
	FILE *p;
	p = fopen("admin.bin","ab+");
	c = (data*)malloc(sizeof(data));
	m = (data*)malloc(sizeof(data));
	printf("\n");
		
			a:printf("Enter the Student's Admission Number:- ");
			scanf("%d",&m->admn);
			if(m->admn==0)
			{
				printf("\t\t\t\tReturning to Main Menu...");
				Sleep(1000);
				system("cls");
				return;
			}
			fflush(stdin);
			printf("Enter the Student's USN:- ");
			scanf("%s",m->usn);
			rewind(p);
			for(;;)
			{
				fread(c,sizeof(data),1,p);
				if(feof(p))
				break;
			 	else if((m->admn==c->admn)||(strcmp(m->usn,c->usn)==0))
				{
				printf("\t\t\t\t\tALREADY REGISTERED..\n\n");
				goto a;
				}
			}
			printf("Enter student's name\n");
			fflush(stdin);
			gets(m->name);
			fwrite(m,sizeof(data),1,p);

		fclose(p);
		free(m);
		free(c);
printf("\n\t\t\t\t\t...DATABASE UPDATED SUCCESSFULLY...\n\n");
}

int signin()
{
	FILE *p;
	p = fopen("admin.bin","ab+");
	int flag=0;
	data *m,*c;
	m = (data*)malloc(sizeof(data));
	c = (data*)malloc(sizeof(data));
	
	again:printf("Enter your Login Id : ");
	scanf("%s",m->usn);
	printf("Enter your Password : ");
	scanf("%d",&m->admn);
	rewind(p);
	for(;;)
			{
				
				fread(c,sizeof(data),1,p);
				if(feof(p))
				break;
				
				else if((strcmp(m->usn,c->usn)!=0)||(m->admn!=c->admn))
				flag=1;
				else
				return(c->admn);
				
			}	
	if(flag==1)
	{
	printf("\t\t\t\t\tGive correct credentials....\n");
	goto again;
	
	}
}


main()
{
	int choice, choose, w;
	printf("\t\t\t\tWelcome To Student Portal\n\n");
	a:printf("1.Registration\t\t2.Sign In\t\t3.Exit\n");
	scanf("%d",&choice);
	switch(choice)
	{

		case 1:registration();
		break;
		
		case 2: w = signin();
			system("cls");
				printf("1.Tests\t\t2.Scores\n");
				scanf("%d",&choose);
				switch(choose)
				{
				//	case 1:	
				//		test(w);													//Used to link this main interface with Student portal.
				//		break;
				//	case 2: 
				//		score_card(w);												//Score Portal not coded
				//		break;	
				}		
		break;
		case 3: 
		printf("Bye!\n");
		Sleep(2000);
		exit(0);
			
		
	}
  
goto a;
}