Queue using linked list

//program to implement queue using linked list

#include
#include
#include

class queue
{
struct node
{
int data;
node *link;
}*front,*rear;

public:
queue();
void enqueue(int);
void dequeue();
void display();
~queue();
};

queue::queue()
{
front=rear=NULL;
}

void queue::enqueue(int item)
{
node *temp;
temp=new node;

if(temp==NULL)
{
cout<<"\nQueue is Full.....cannot insert";
return;
}

temp->data=item;
temp->link=NULL;
if(front==NULL)
{
front=rear=temp;
}
else
{
rear->link=temp;
rear=temp;
}
}

void queue::dequeue()
{
node *temp;

if(front==NULL)
{
cout<<"\nThe Linked Queue is empty";
return;
}

temp=front;
cout<<"\nThe element deleted from linked queue ";
cout<data;
front=front->link;
delete(temp);
}

void queue::display()
{
node *temp;

temp=front;
cout<<"\nThe linked queue is now\n";
while(temp!=NULL)
{
cout<data<<"<--";
temp=temp->link;
}
}

queue::~queue()
{
node *temp;

if(front==NULL)
{
return;
}
while(front!=NULL)
{
temp=front;
front=front->link;
delete(temp);
}
}

void main()
{
int ch,item;
queue q1;

do
{
cout<<"\n------------Linked Queue Operations-------------\n";
cout<<"\n1_Enqueue";
cout<<"\n2_Dequeue";
cout<<"\n3_Display";
cout<<"\n4_Exit";
cout<<"\nEnter your choice<1-4>:";
cin>>ch;

switch(ch)
{
case 1:
cout<<"\nEnter the item to be inserted:";
cin>>item;
q1.enqueue(item);
break;

case 2:
q1.dequeue();
break;

case 3:
q1.display();
break;

case 4:
exit(0);
break;

default:
cout<<"\nInvalid choice";
break;
}
}while(ch!=4);
getch();
}