single link_list program in c++

#include<iostream.h>
#include<conio.h>
#include<stdlib.h>


class list
{
 struct node
 {
  int data;
  node *link;
 }*p;
public:
 void inslast(int);
 void insbeg(int);
 void insnext(int,int);
 void delelement(int);
 void delbeg();
 void dellast();
 void disp();
 int seek(int);
 list(){p=NULL;}
 ~list();
};

void list::inslast(int x)
{
 node *q,*t;
 if(p==NULL)
 {
  p=new node;
  p->data=x;
  p->link=NULL;
 }
 else
 {
  q=p;
  while(q->link!=NULL)
   q=q->link;
  t=new node;
  t->data=x;
  t->link=NULL;
  q->link=t;
 }
 cout<<"Inserted successfully at the end..";
 disp();
}

void list:: insbeg(int x)
{
 node *q;
 q=p;
 p=new node;
 p->data=x;
 p->link=q;
 cout<<"
 Inserted successfully at the begining..";
 disp();
}


void list::delelement(int x)
{
 node *q,*r;
 q=p;
 if(q->data==x)
 {
  p=q->link;
  delete q;
  return;
 }
 r=q;
 while(q!=NULL)
 {
  if(q->data==x)
  {
   r->link=q->link;
   delete q;
   return;
  }
  r=q;
  q=q->link;
 }
 cout<<"
 Element u entered   "<<x<<"    is not found..";
}

void list:: delbeg()
{
 cout<<" The list before deletion:";
 disp();
 node *q;
 q=p;
 if(q==NULL)
 {
  cout<<" No data is present..";
  return;
 }
 p=q->link;
 delete q;
 return;
}


void list:: dellast()
{
 cout<<"
 The list before deletion:";
 disp();
 node *q,*t;
 q=p;
 if(q==NULL)
 {
  cout<<"
 There is no data in the list..";
  return;
 }
 if(q->link==NULL)
 {
  p=q->link;
  delete q;
  return;
 }

 while(q->link->link!=NULL)
  q=q->link;
 q->link=NULL;
 return;
}

list::~list()
{
 node *q;
 if(p==NULL) return;
 while(p!=NULL)
 {
  q=p->link;
  delete p;
  p=q;
 }
}

void list::disp()
{
 node *q;
 q=p;
 if(q==NULL)
 {
  cout<<" No data is in the list..";
  return;
 }
 cout<<" The items present in the list are :";
 while(q!=NULL)
 {
  cout<<" "<<q->data;
  q=q->link;
 }
}

void list :: insnext(int value,int position)
{
 node *temp,*temp1;
 temp=p;
 if(temp1==NULL)
 {
  temp1= new node;
  temp1->data=value;
  temp1->link=NULL;
  p=temp1;
  return;
 }
 for(int i=0;((i<position)&&(temp->link!=NULL)) ;i++)
 {
  if(i==(position-1))
  {
   temp1= new node;
   temp1->data= value;
   temp1->link=temp->link;
   temp->link=temp1;
  }
  temp=temp->link;
 }
 //cout<<" Inserted successfully at the position.."<<position;
 disp();
}


int list::seek(int value)
{
 node *temp;
 temp=p;
 int position=0;
 while(temp!=NULL)
 {
  if(temp->data==value)
   return position+1;
  else
  {
   temp=temp->link;
   position=position+1;
  }
 }
 cout<<" Element "<<value<<" not found";
 return 0;
}


void main()
{
list l;
int ch,v,p,ps;
do
{
 clrscr();
 cout<<" Operations on List..";
 cout<<"
1.Insertion
2.Deletion
3.Display
4.Seek
5.Exit";
 cout<<" Enter ur choice:";
 cin>>ch;

 switch(ch)
 {
 case 1:
  cout<<"1.Insertion at begining 2.Insertion at the end";
  cout<<"3.Insertion after the mentioned position";
  cout<<" Enter ur choice:";
  cin>>ps;
  cout<<" Enter the value to insert:";
  cin>>v;
  switch(ps)
  {
   case 1:
    l.insbeg(v);
    break;
   case 2:
    l.inslast(v);
    break;
   case 3:
    cout<<" Enter the position to insert the value:";
    cin>>p;
    l.insnext(v,p);
    break;

   default:
    cout<<" The choice is invalid";
    return;
  }
 break;

 case 2:
  cout<<"1.Delete the first element 2.Delete the last element";
  cout<<"3.Enter the element to delete from the list";
  cout<<" Enter ur choice:";
  cin>>ps;
  switch(ps)
  {
   case 1:
    l.delbeg();
    cout<<" The list after deletion:";
    l.disp();
    break;
   case 2:
    l.dellast();
    cout<<" The list after deletion:";
    l.disp();
    break;
   case 3:
    l.disp();
    cout<<" Enter the element to delete : ";
    cin>>v;
    l.delelement(v);
    cout<<" The list after deletion:";
    l.disp();
    break;

   default:
    cout<<" The option is invalid...";
    break;
  }
 break;

 case 3:
  l.disp();
  break;

 case 4:
  l.disp();
  cout<<" Enter the element to search:";
  cin>>v;
  cout<<" The position of the element "<< v<<"  is "<<l.seek(v);
  getch();
  break;

 case 5:
  exit(1);

 default:
  cout<<" The option is invalid...";
  return;
 }
 getch();
}while(ch!=5);
getch();
return;
}