程序运行后，找不到文件。不知道哪里出错。代码也不知道怎么改！这样写代码有什么问题？要怎么解决？
    具体代码如下：
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <ctype.h>

#define NAME_LEN        21
#define TEL_LEN         11

typedef struct Record Record;

struct Record
{
    char name[NAME_LEN];
    char Tel[TEL_LEN];
    Record *next;
};

Record *get_person(Record *pcurrent);
void get_name(char *pname, size_t size);
void write_file(Record *first, char *filename, FILE *pfile);
void free_record(Record *first);

int main(void)
{
    Record *first = NULL;
    Record *current = NULL;
    Record *previous = NULL;
    char more = '\0';
   
    printf("这是一个从键盘读入姓名和电话号码，将它们写入一个文件的程序！\n");
   
    while(true)
    {
        printf("现在请确认是否有从键盘读入姓名和电话号码：Y：是！N：否！ ");
        scanf(" %c", &more);
        fflush(stdin);
        
        if(toupper(more) == 'N')
          break;
         
        if(first == NULL)
          first = current;
         
        if(previous != NULL)
          previous -> next = current;
         
        get_person(current);
        previous = current;
    }
   
    FILE *pfile = NULL;
    char *filename = "myTel.txt";
   
    write_file(first, filename, pfile);
   
    free_record(first);
   
    return 0;
}

Record *get_person(Record *pcurrent)
{
    pcurrent = (Record*)malloc(sizeof(Record));
    if(!pcurrent)
    {
        printf("没有分配内存！\a\a\a\n");
        exit(1);
    }
   
    printf("现在从键盘读入不超过 %d 字节姓名： ", NAME_LEN - 1);
    get_name(pcurrent -> name, NAME_LEN);
    printf("现在从键盘读入%s的电话号码： ", pcurrent -> name);
    get_name(pcurrent -> Tel, TEL_LEN);
    pcurrent -> next = NULL;
   
    return pcurrent;
}

void get_name(char *pname, size_t size)
{
    fflush(stdin);
    fgets(pname, size, stdin);
   
    size_t len = strlen(pname);
   
    if(pname[len - 1] == '\n')
      pname[len - 1] = '\0';
}

void write_file(Record *first, char *filename, FILE *pfile)
{
    Record *pcurrent = NULL;
    for(pcurrent = first; pcurrent != NULL; pcurrent = pcurrent -> next)
    {
        if(!(pfile = fopen(filename, "a")))
        {
            fprintf(stderr, "打开%s文件不成功！\a\a\a\n", filename);
            exit(1);
        }
        setvbuf(pfile, NULL, _IOFBF, BUFSIZ);
        
        size_t len_name = strlen(pcurrent -> name);
        
        if(EOF == fputs(pcurrent -> name, pfile))
        {
            fprintf(stderr, "%s写入%s文件不成功！\a\a\a\n", pcurrent -> name, filename);
            exit(1);
        }
        
        int i = 0;
        for(i = 0; i < NAME_LEN - len_name; ++i)
        {
            char ch1 = ' ';
            if(EOF == fputc(ch1, pfile))
            {
                fprintf(stderr, "写入%s文件不成功！\a\a\a\n", filename);
                exit(1);
            }
        }
        
        if(EOF == fputs(pcurrent -> Tel, pfile))
        {
            fprintf(stderr, "电话号码写入%s文件不成功！\a\a\a\n", filename);
            exit(1);
        }
        
        char ch2 = '\n';
        if(EOF == fputc(ch2, pfile))
        {
            fprintf(stderr, "写入%s文件不成功！\a\a\a\n", filename);
            exit(1);
        }
        
        fclose(pfile);
        pfile = NULL;
    }
}

void free_record(Record *first)
{
    Record *pcurrent = NULL;
    Record *previous = NULL;
   
    pcurrent = first;
   
    while(pcurrent != NULL)
    {
        previous = pcurrent;
        pcurrent = pcurrent -> next;
        
        free(previous);
        previous = NULL;
    }
   
    free(first);
    first = NULL;
}

    我已按照你说改过来。这回是找得到文件，可是文件只显示好几百条第一个记录，并且运行程序后不能正常结束！程序是不是还有其它更重要的问题？