Priority Queue Implementation: C source codes

A priority queue is data structure in which intrinsic ordering of the elements does determine the results of its basic operations. These are of two types- ascending (e.g. queue) and descending (e.g. stack).
The following source code implements ascending type priority queue in C:

// Ascending Priority Queue Implementation in C

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

    const int MAX=5;

    class pqueue
    {
          int front,rear;
        public:
          struct data
          {
           int val,p,o;
          }d[MAX];

         pqueue()
         {
            front=rear=-1;
         }
         void insert(data d1);
         data deletion();
         void display();
    };
    void pqueue :: insert(data d1)
    {
        if(rear==MAX-1)
           cout<<"Priority Queue is Full
";
        else
        {
           rear++;
           d[rear]=d1;
           if(front==-1)
              front=0;
           data temp;
           for(int i=front;i<=rear;i++)
             for(int j=i+1;j<=rear;j++)
             {
                 if(d[i].p > d[j].p)
                 {
                    temp=d[i];
                    d[i]=d[j];
                    d[j]=temp;
                 }
                 else
                 {
                     if(d[i].p==d[j].p)
                     {
                         if(d[i].o > d[j].o)
                         {
                              temp=d[i];
                              d[i]=d[j];
                              d[j]=temp;
                         }
                     }
                 }
             }
        }
    }
    data pqueue :: deletion()
    {
        data d1;
        if(front==-1)
           cout<<"Priority Queue is Empty
";
        else
        {
           d1=d[front];
           if(front==rear)
              front=rear=-1;
           else
              front++;
        }
        return d1;
    }
    void pqueue :: display()
    {
         if(front==-1)
             cout<<"Priority Queue is Empty
";
         else
         {
            for(int i=front;i<=rear;i++)
            {
                cout<<"Object  :"<<i+1<<endl;
                cout<<"Value ="<<d[i].val<<endl;
                cout<<"Priority="<<d[i].p<<endl;
                cout<<"Order =  "<<d[i].o<<endl;
            }
         }
    }
    void main()
    {
      pqueue p1;

      data d1;
      char op;
      do
      {
        int ch;

        clrscr();
        cout<<"----------Menu-------------
";
        cout<<"1.Insertion
2.Deletion
3.Display
4.Exit
";
        cout<<"Enter your Choice<1..4> ?";
        cin>>ch;
        switch(ch)
        {
           case 1 :  cout<<"Enter Value ?";
                     cin>>d1.val;
                     cout<<"Enter Priority?";
                     cin>>d1.p;
                     cout<<"Enter Order ?";
                     cin>>d1.o;
                     p1.insert(d1);
                     break;
           case 2 :  d1=p1.deletion();
                     cout<<"Value = "<<d1.val<<endl;
                     cout<<"Priority = "<<d1.p<<endl;
                     cout<<"Order ="<<d1.o<<endl;
                     break;
           case 3 :  p1.display();
                     break;
          }
          cout<<"Do You Want to Continue <Y/N> ?";
          cin>>op;
        }while(op=='Y' || op=='y');
        getch();
      }