linked list in c++

#include<iostream.h>
struct list
{
int d;list*next;
}*head,*node,*tail,*k;
void make_list();
void print_list();
void add_infirst();
void add_after();
void delet_last();
void delet_first();

main()
{int n;
for(; ;)
{
cout<<"---------(Menu)-----------\n";
cout<<"_________________________";
cout<<"\nenter(1)|to creat list|";
cout<<"\nenter(2)|to add list infirst|";
cout<<"\nenter(3)|to print list|";
cout<<"\nenter(4)|to add list after data|";
cout<<"\nenter(5)|to delete last|";
cout<<"\nenter(6)|to delete first|";
cout<<"\nenter(7)|to exit|";
cout<<"\n_________________________\n";
cin>>n;
switch(n)
{
case 1:make_list();break;
case 2:add_infirst();break;
case 3:print_list();break;
case 4:add_after();break;
case 5:delet_last();break;
case 6:delet_first();break;
case 7:return(0);}}}
//__________________________________________________to creat list
void make_list()
{int n,i=0;
cout<<"\nenter number list you make:";cin>>n;
node=new list;
node->next=NULL;
cin>>node->d;
tail=head=node;
while(i<n-1)
{
node=new list;
cin>>node->d;
node->next=NULL;
tail->next=node;
tail=node;
i++;}}
//__________________________________________________to print list
void print_list()
{
int i=1;
node=head;
while(node!=NULL)
{
cout<<"\n"<<i++<<"-->"<<node->d;
node=node->next;}}
//_________________________________________________to add infirst list
void add_infirst()
{node=head;
k=new list;
k->next=node;
cout<<"\nenter data infirst:";
cin>>k->d;
head=k;
}
//_____________________________________to add list after data you enter
void add_after()
{node=k=head;
int n;
cout<<"\nenter data to serch:";
cin>>n;
while(node!=NULL)
{if(node->d==n)
{k=new list;
k->next=node->next;
node->next=k;
cout<<"enter data of list";
cin>>k->d;break;}node=node->next;
}cout<<"\ndata non found\n";}
//____________________________________to delete last
void delet_last()
{
k=node=head;
while(node)
{
if(node->next==NULL)
{
k->next=NULL;
delete node;
break;}
k=node;
node=node->next;}}
void delet_first()
{
node=head;
head=head->next;
delete node;
}