How to make registration form in C language?

#include <stdio.h>
#include <conio.h>
#include <stdlib.h>
#include <string.h>
void get_ID_and_PASS(char fileName[30],char *id,char *pass)
{
 FILE *F = fopen(fileName,"r");
if(F)
{
 int count = 0;
while(!feof(F))
{
 char rawLine[50];
 fscanf(F,"%s",rawLine);
if(!count++)
 strcpy(id,rawLine);
else
 strcpy(pass,rawLine);
}
}else printf("Cannot open this file");
fclose(F);
}
int main()
{
 char c;
 int pos = 0;
 char fileName[30] = "user.txt";
 char userID[50],userPassW[50];
 char strID[50]="\0",strPASSW[50]="\0";

 char IDpref[50] = "user_id:\0",PASSWpref[50] = "password:\0";
get_ID_and_PASS(fileName,userID,userPassW);
 printf("\n\n");
 printf("\tRegistration Form in C language");
 printf("\n\n");
 printf("\tEnter Your User Name: ");
 scanf("%s",&strID);
 printf("\n");
 printf("\tEnter Your Password: ");
do {
 c = getch();
if( isprint(c) ) 
{
 strPASSW[ pos++ ] = c;
 printf("%c", '*');
}
else if( c == 9 && pos )
{
 strPASSW[pos--] = '\0';
 printf("%s", "\b \b");
}
} while( c != 13 );
 strcpy(strID,strcat(IDpref,strID));
 strcpy(strPASSW,strcat(PASSWpref,strPASSW));
if(!strcmp(strID,userID)&&!strcmp(strPASSW,userPassW))
{
 printf("\n\n");
 printf("\tCorrect Username And Password\n");
 printf("\n\n\tWelcome to Our Registration System\n\n"); 
}
else
{
  printf("\n\n");
  printf("\tInvalid Username And Password. Try Again\n\n");
 }
  printf("\n\n");
  printf("\tEND OF PROGRAM");
  printf("\n\n");
  system("pause");
}

Output:

How to make registration form in C language