How to make registration form in C language?

#include<stdio.h>
#include<conio.h>
#include<string.h>
#include<stdlib.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: