哪位高手能帮小弟我看看这代码错哪了。

谁能帮我看看这代码哪里错了。。。
#include<stdio.h>
#include<stdlib.h> /*标准函数库*/
#include<conio.h>/*屏幕操作函数*/
#define LEN sizeof(struct txt)

void newtxt();/*新建文件*/
void displaytxt();/*显示文件*/
void modifytxt();/*修改数据*/

void main()
{  
struct txt{
int num;
char word;
struct txt * next;
};
  int c;
printf("*************菜单**************\n");
printf("1.新建文件 \n");
printf("2.显示数据\n");  
printf("3.修改数据\n");  
printf(" 4.退出(任何情况下按Ctrl+C退出程序)\n");
 
do
{  
printf("\n\t\t 输入你的选择(1-4):");
scanf("%d",&c);
}while(c<0||c>4);
switch(c)
{
case 1: system("cls"); newtxt();break;
case 2: system("cls"); displaytxt();break;
case 3: system("cls"); modifytxt();break;
case 4: exit(0);
}
}
void newtxt()/*新建文件*/
{
printf("请输入文件名：");
char name[32];
scanf("%s",name);
system("cls");
printf("请输入数据，输入#号键后按回车结束\n");
FILE *fp;
fp=fopen(name,"w");

char ch;
while((ch=getchar())!='#')
{
fputc(ch,fp);
}
fputc('#',fp);
fclose(fp);

printf("\n\t\t按任意键返回......\n");
getch();
system("cls"); /*清屏*/
return;
}  
void displaytxt()/*显示文件*/
{
printf("请输入文件名：");
char name[32];
scanf("%s",name);
system("cls");
FILE *fp;
fp=fopen(name,"r");

char ch;
while((ch=fgetc(fp))!='#')
{
putchar(ch);
}
fclose(fp);

printf("\n\t\t\t按任意键返回......\n");
getch();
system("cls"); /*清屏*/
return;
}
void modifytxt()

{ struct txt{
int num;
char word;
struct txt * next;
};
  struct txt * del(struct txt *head);
struct txt * insert(struct txt *head);
struct txt * replace(struct txt *head);  
   
printf("请输入文件名：");
char name[32],ch;
scanf("%s",name);
system("cls");
FILE *fp;
fp=fopen(name,"r");
struct txt *head;
struct txt *p1,*p2,*p; 
int n=0; 
head=NULL;
p1=p2=(struct txt *)malloc(LEN);
p1->num=0; 
  while((ch=fgetc(fp))!='#') 
{ n++;
p1->num++;
p1->word=ch;
if(n==1) head=p1;
else p2->next=p1;
p2=p1;
p1=(struct txt *)malloc(LEN);
}
 
p1->num++;
p1->word='#';
p2=p1;
p2->next=NULL;
fclose(fp);
int j,i;
   



p=head;
for(j=1;j<n;j++)
printf("%c",p->word);
printf("请选择选项：\n");
printf("1.删除；\n");  
printf("2.插入；\n");
printf("3.替换；\n");
printf("4.退出；\n");
scanf("%d",&i);
switch(i)
{
case '1':system("cls");struct txt * del(struct txt *head);n=n-1;break;

case '2':system("cls");struct txt * insert(struct txt *head);n=n+1;break;
 
case '3':system("cls");struct txt * replace(struct txt *head);break;  
 
case '4':system("cls");exit(0);
}
 
printf("请输入文件名：");
scanf("%s",name);
system("cls");
FILE *fp1;
fp1=fopen(name,"w");
p1=head;