#include<stdio.h>
#define size 21
#define max 10

typedef struct id
 {
  int idnum,q1,q2,q3;
  char fn[size];
  char ln[size];
  char mi[2];
  float ave;
 }id;
  id l[max];
  id a;

int menu()
{
 int i,s=0;
    while(s<1 || s>4)
    {
     clrscr();
     gotoxy(5,5);
     printf("MENU");
     gotoxy(5,7);
     printf("1. insert");
     gotoxy(5,9);
     printf("2. delete");
     gotoxy(5,11);
     printf("3. display");
     gotoxy(5,13);
     printf("4. exit");
     gotoxy(5,15);
     printf("select 1-4: ");scanf("%d",&s);
    }
    return (s);
  }

  void initialize()
  {
   int i;
   for(i=0;i<max;i++);
    l[i].idnum=-1;
  }

  int end()
   {
    int i=0;
    while(l[i].idnum!=-1)
     i++;
    return(i);
   }

  void insert(id a)
  {
   int i,p;
   i=p=0;
   while(a.idnum>l[i].idnum && l[i].idnum!=-1)
      i++;
    if (l[i].idnum==-1)
     {
      l[p].idnum=a.idnum;
      strcpy(l[p].fn,a.fn);
      strcpy(l[p].ln,a.ln);
      strcpy(l[p].mi,a.mi);
      l[p].q1=a.q1;
      l[p].q2=a.q2;
      l[p].q3=a.q3;
      l[p].ave=(float)(a.q1+a.q2+a.q3)/3.0;
     }
    else{
      for(i=end();i>p;i--);
      {
      l[i].idnum=l[i-1].idnum;
      strcpy(l[i].fn,l[i-1].fn);
      strcpy(l[i].ln,l[i-1].ln);
      strcpy(l[i].mi,l[i-1].mi);
      l[i].q1=l[i-1].q1;
      l[i].q2=l[i-1].q2;
      l[i].q3=l[i-1].q3;
      l[i].ave=l[i-1].ave;
      }
      l[p].idnum=a.idnum;
      strcpy(l[p].fn,a.fn);
      strcpy(l[p].ln,a.ln);
      strcpy(l[p].mi,a.mi);
      l[p].q1=a.q1;
      l[p].q2=a.q2;
      l[p].q3=a.q3;
      l[p].ave=(float)(a.q1+a.q2+a.q3)/3.0;
      }
      getch();
    }

    void delete(id a)
    {
     int i,p;
     i=p=0;
     clrscr();
     while(a.idnum!=l[i].idnum && l[i].idnum!=-1)
     i++;
    p=i;
     if(l[i].idnum==-1)
     {
     printf("record not found");
     getch();
         }
     else
     for(i=p;i<end();i++)
     {
      l[i].idnum=l[i+1].idnum;
      strcpy(l[i].fn,l[i+1].fn);
      strcpy(l[i].ln,l[i+1].ln);
      strcpy(l[i].mi,l[i+1].mi);
      l[i].q1=l[i+1].q1;
      l[i].q2=l[i+1].q2;
      l[i].q3=l[i+1].q3;
      l[i].ave=l[i+1].ave;
      }

    }
  void displayall()
  {
  int i;
  printf("idnum    1stnme    lastnme     midtial       q1      q2      q3    average");
  for(i=0;i<end();i++)
  {
    gotoxy(1,i+3);
    printf("%d",l[i].idnum);
    gotoxy(10,i+3);
    printf("%s",l[i].fn);
    gotoxy(20,i+3);
    printf("%s",l[i].ln);
    gotoxy(32,i+3);
    printf("%s",l[i].mi);
    gotoxy(46,i+3);
    printf("%d",l[i].q1);
    gotoxy(55,i+3);
    printf("%d",l[i].q2);
    gotoxy(63,i+3);
    printf("%d",l[i].q3);
    gotoxy(68,i+3);
    printf("%.2f",l[i].ave);
    }
    getch();
 }

 main()
 {
 int i;
 id b;
 initialize();
 while(1)
 {
 i=menu();
 if(i==1)
  { clrscr();
    printf("\n input id number: "); scanf("%d",&b.idnum);
    printf("input firstname: "); scanf("%s",b.fn);
    printf("input lastname: "); scanf("%s",b.ln);
    printf("input mid initial: "); scanf("%s",b.mi);
    printf("input quiz1:");scanf("%d",&b.q1);
    printf("input quiz2:");scanf("%d",&b.q2);
    printf("input quiz3:");scanf("%d",&b.q3);
    insert(b);}
 else
   if(i==2) {
    clrscr();printf("input id number:");scanf("%d",&b.idnum);
    delete(b);  }
 else
   if(i==3){
   clrscr();displayall();}
 else
   exit(0);

 getch();
 }
}

 void insert(id* a)
{
...
<snip>
while(a->idnum > l[i].idnum && l[i].idnum != -1)