Play with Words

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

struct PLAYER {
    char NAME[12];
    char PASSWORD[12];
};

void menu_message() {
    puts("+----------------------------------------------+");
    puts("|              ~  GAME OF WORDS ~              |");
    puts("| Increase your vocabulary playing with words! |");
    puts("| 1. Login to continue                         |");
    puts("| 2. Register new player                       |");
    puts("| Enter any other letter to exit               |");
    puts("+----------------------------------------------+");
}

struct PLAYER register_message() {
    puts("+--------------------------+");
    puts("| Enter player information |");
    puts("+--------------------------+");

    struct PLAYER NEW_PLAYER;

    printf(" Username: ");
    scanf("%s", NEW_PLAYER.NAME);

    printf(" Password: ");
    scanf("%s", NEW_PLAYER.PASSWORD);

    return NEW_PLAYER;
}

void back_to_menu_message() {
    puts("+------------------+");
    puts("| 1. Back to menu  |");
    puts("| 2. Start playing |");
    puts("+------------------+");
}

void start_message() {
    puts("+--------------------------------------+");
    puts("|          ~ START PLAYING ~           |");
    puts("| Form english words using the letters |");
    puts("| provided, choose the number of       |");
    puts("| letters the word should have.        |");
    puts("| Enter the word \"quit\" to stop!       |");
    puts("+--------------------------------------+");
}

int find_word(char WORD[12]) {
    char STRING[50];
    int COUNT = 0;

    FILE *in_file = fopen("words.txt", "r");

    if (in_file == NULL) {
        printf("Error file missing\n");
        exit(0);
    }

    while(!feof(in_file)) { //this loop searches the for the current word
        fscanf(in_file,"%s",STRING);
        if(!strcmp(STRING,WORD)) COUNT++; //if match found increment num
    }
    return COUNT;
}

int find_player(char NAME[12], char PASSWORD[12]) {
    FILE * MY_FILE = fopen("players.txt","r");
    char FILE_NAME[12], FILE_PASSWORD[12];
    int RESULT;

    if(MY_FILE != NULL) {
        while(!feof(MY_FILE)) {
            fscanf(MY_FILE,"%s\t%s", FILE_NAME, FILE_PASSWORD);

            if(strcmp(NAME, FILE_NAME) == 0 && strcmp(PASSWORD, FILE_PASSWORD) == 0) RESULT++;
        }
    }
    return RESULT;
}

int start_scrabble() {
    int CHOICE, NUMBER_OF_LETTERS;
    struct PLAYER MY_PLAYER;
    char MENU[12] = {"Menu"}; // default value
    char WORD[12] = {"Empty"};
    FILE * MY_FILE;

    while(strcmp(MENU, "Menu") == 0) {
        menu_message(); // menu
        scanf("%d", &CHOICE);

        switch(CHOICE) {
        case 1:
            puts("+--------------------------+");
            puts("| Enter player information |");
            puts("+--------------------------+");

            printf(" Username: ");
            scanf("%s", MY_PLAYER.NAME);

            printf(" Password: ");
            scanf("%s", MY_PLAYER.PASSWORD);

            if (find_player(MY_PLAYER.NAME, MY_PLAYER.PASSWORD) > 0) {
                start_message();
                printf(" Number of letters: ");
                scanf("%d", &NUMBER_OF_LETTERS);

                do {
                    printf("> ");
                    scanf("%s", WORD);

                    if (find_word(WORD) == 0) {
                        if (strlen(WORD) == NUMBER_OF_LETTERS) puts(" [Try again!]");
                        else printf("[The word should have %d words!]\n", NUMBER_OF_LETTERS);

                    } else puts(" [Good job!]");
                } while(strcmp(WORD, "quit") != 0);
                if(strcmp(WORD, "quit") == 0) exit(0);
            }

            break;
        case 2:
            MY_PLAYER = register_message(); // registration

            MY_FILE = fopen("players.txt","a+");
            fprintf(MY_FILE,"%s\t%s\n",MY_PLAYER.NAME, MY_PLAYER.PASSWORD);

            back_to_menu_message();
            scanf("%d", &CHOICE);

            switch(CHOICE) {
            case 1:
                strcpy(MENU, "Menu");
                break;
            case 2:
                start_message();
                printf(" Number of letters: ");
                scanf("%d", &NUMBER_OF_LETTERS);

                do {
                    printf("> ");
                    scanf("%s", WORD);

                    if (find_word(WORD) == 0) {
                        if (strlen(WORD) == NUMBER_OF_LETTERS) puts(" [Try again!]");
                        else printf("[The word should have %d words!]\n", NUMBER_OF_LETTERS);

                    } else puts(" [Good job!]");
                } while(strcmp(WORD, "quit") != 0);

                strcpy(MENU, "Start playing");
                break;
            }

            break;
        default:
            exit(0);
        }
    }

    return 0;
}