ช่วยดู code ให้หน่อยคับ

ช่วยดูที คับว่า เขียนผิด รึป่าว
ผมรันไม่ได้ ไม่รู้เป็นอะไร

#include<stdio.h>
int num;
char ans;
int sum;
int z;
struct food{char name[20];
int age;
}fd;

void insert_name();
void main()

{
clrscr();
void insert_name()
{
FILE *fp;
char tmp[3];
if((fp=fopen(\"customer.txt\",\"a+t\"))==NULL)
{
printf(\"Cannot open file for insert data\\n\");
getch();
exit(1);
}

printf(\"Name customer :\");
gets(fd.name);
printf(\"Age :\");
gets(tmp);
fd.age=atof(tmp);
fwrite(&fd,sizeof(fd),1,fp);
if(ferror(fp))
{
printf(\"Error for insert name\\n\");
getch();
exit(1);
fclose(fp);
}

printf(\"What do you want to eat??\\n\");
printf(\"1.Hamburger\\n2.Hotdog\\n3.Fried chicken\\n4.Pizza\\n5.Sandwich\\n6.Exit\\n\");
printf(\"Please enter number:\");
scanf(\"%d\",&num);
printf(\"How many :\");
scanf(\"%d\",&z);
if(num==1)
{
printf(\"You want Hamburger is 50 Bath\");
sum = z*50;
printf(\"\\nTotal is %d\",sum);
}
else if(num==2)
{
printf(\"You want Hotdog is 30 Bath\");
sum = z*30;
printf(\"\\nTotal is %d\",sum);
}
else if(num==3)
{
printf(\"You want Fried chicken is 40 Bath\");
sum = z*40;
printf(\"\\nTotal is %d\",sum);
}
else if(num==4)
{
printf(\"You want Pizza is 90 Bath\");
sum = z*90;
printf(\"\\nTotal is %d\",sum);
}
else if(num==5)
{
printf(\"You want Sandwich is 30 Bath\");
sum = z*30;
printf(\"\\nTotal is %d\",sum);
}
else
{
exit();
}
getch();
}
}