линейные списки, удаление последнего эллемента списка

#include <iostream.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
struct Elem {int data; Elem*next;};
Elem*create (int n)
{Elem*pb = new Elem; pb -> data = n; pb -> next = 0; return pb;}
void showlist ( Elem*pb)
{Elem*p = pb;
while (p)
 {cout<<" "<<p->data<<" "; p = p->next;}}
Elem*insfirst (Elem*pb, int n)
{Elem *p = new Elem; p->data = n; p->next=pb; pb = p; return pb;}
Elem*del_last_el (Elem*pb)
{
  }
 
return pb;}
Elem*preobr (Elem*pb)
{Elem *p = pb;
while (p)
 {p->data+=2; p=p->next;}
cout<<" done"; getch(); return pb;
}
void save_list (Elem *pb)
{ char path[20]; FILE*fn;
cout<<"path:"; cin>>path;
if ((fn=fopen(path,"w"))==NULL)
 {cout<<"cannot open output file.\n"; getch(); return;}
Elem*p = pb;
while (p)
 {fprintf(fn,"%d\n", p->data); p= p->next;}
fclose(fn); cout<<" done"; getch();
}
Elem* load_list (void)
{char path[20]; FILE* fn; int n;
cout<<"path:"; cin>>path;
if ((fn=fopen(path,"r"))==NULL)
 {cout<<"cannot open output file.\n"; getch(); return 0;}
Elem*p,*pb = new Elem;
fscanf(fn, "%d\n", &n); pb->data = n; pb->next=0;
while (!feof(fn))
 {fscanf(fn, "%d\n", &n); p= new Elem; p->data = n; p->next = pb;
   pb=p;}
fclose(fn); cout<<" done"; getch(); return pb;
}
int menu(void)
{Elem*pb; char choice; int n;
begin: clrscr(); cout<<"\n";
cout<<"\n 1. Create list";
cout<<"\n 2. Append in list";
cout<<"\n 3. Show list";
cout<<"\n 4. Action";
cout<<"\n 5. Save list to file";
cout<<"\n 6. Load list from file";
cout<<"\n 7. delete every 2 element";
cout<<"\n 8. Finish";
cout<<"\n \n Your choice: "; choice=getch();
switch (choice)
 {case '1': clrscr();
  cout<<"\n number: "; cin>>n; pb= create(n); break;
  case '2': clrscr();
  cout<<"\n number: "; cin>>n; pb= insfirst(pb,n); break;
  case '3': clrscr();
  showlist(pb); getch(); break;
  case '4':
  pb=preobr(pb); break;
  case '5': clrscr();
  save_list(pb); break;
  case '6': clrscr();
  pb=load_list(); break;
  case '7': clrscr(); del_every_2el (pb); break;
  case '8': return 0;
 }
goto begin;
}
void main (void)
{clrscr(); menu();}