Help on dqueue program

In the below attached code, while adding using option 1, option 3&4 to print works ok. But after using opton 2 (dqueue), the printing options 3&4 does not work ok. Where am I making the mistake.



after selecting option 2 to dequeue, option 3 and

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


/* ------------------------------------------------------- */
/* Definitions */

#define READAHEAD 1
#define READBACK 2

typedef struct queuenode
{
      int val;
      struct queuenode *next,*prev;
}node;

node *front=NULL, *rear=NULL;


/* ------------------------------------------------------- */
/* Declarations */
void enqueue(int);
int dequeue(void);
void printqueue(char);


/* ------------------------------------------------------- */
/* Entry Point - Start here */
void main()
{
      int ch,num;

      do
      {
            /* Read User Input */
            clrscr();
            printf("\n\n  DQUEUE SOLUTION - MAIN MENU");
            printf("\n-----------------------------\n");
            printf("\n1 - ADD (Add value to Queue)");
            printf("\n2 - REMOVE (Remove node from Queue)");
            printf("\n3 - Front to Rear Printing");
            printf("\n4 - Rear to Front Printing");
            printf("\n5 - Exit\n");
            printf("\nChoose the option :- ");

            /* accepting user's choice */
            scanf("%d",&ch);

            switch(ch)
            {
                  case 1: /* inserting value to queue at front */
                        printf("\nEnter the value to Enqueue :- ");
                        scanf("%d", &num);
                        enqueue(num);
                        break;

                  case 2: /* deleting value from rear side of queue */
                        if(front != NULL) /* checking if queue exists */
                        {
                              num=dequeue();

                              /* print the dequeued value */
                              printf("\nThe Dequeued value is - %d.",num);
                        }
                        else
                              printf("\n\nEmpty Queue.");
                        break;

                  case 3: /* printing from front to rear */
                        if(front != NULL)
                        {
                              printf("\nThe Queue from Front to Rear is -\n");
                              printqueue(READAHEAD);
                              getch();
                        }
                        else
                              printf("\n\nEmpty Queue.");
                        break;
                  
                  case 4:
                        if(front != NULL) /* printing from rear to front */
                        {
                              printf("\nThe Queue from Rear to Front is -\n");
                              printqueue(READBACK);
                              getch();
                        }
                        else
                              printf("\n\nEmpty Queue.");
                        break;

                  case 5:
                        break;

                  default:
                        printf("\nKindly enter the correct choice (1-5).");
                        break;
            }
      }while(ch!=5);
}



/* -------------------------------------------------------  */
/* Below function is to add new queues at rear end of the queue */
void enqueue(int num)
{
      node *temp=(node*)malloc(sizeof(node));
      
      temp->val=num;
      temp->next=temp->prev=NULL;

      if(front==NULL)
            front=temp;
      else
      {
            rear->next=temp;
            temp->prev=rear; /* value added after rear  */
      }
      rear=temp; /* rear represents the new member */
}



/* -------------------------------------------------------  */
/* this function deletes the front value from queue and returns it */
int dequeue()
{
      node *temp;
      int delval;

      if(front==NULL)
            return -999;

      temp=front;
      front=front->next; /* front moves to next member in queue */
      
      if(front==NULL)
            rear=NULL; /* rear also changes if there was only one value in queue */
      else
            front->next=NULL;

      delval=temp->val;
      free(temp); /* memory free */
      
      return delval; /* deleted value returned */
}



/* ------------------------------------------------------- */
/* As per user choice, print the queue */

void printqueue(char ch)
{
      node *temp;

      if(front==NULL)
      {
            printf("\n\nEmpty Queue.");
            return;
      }

      /* looping from front to rear or rear to front depending on choice */

for(temp=(ch==READAHEAD?front:rear);temp!=NULL;temp=(ch==READAHEAD?temp->next:temp->prev))
            printf("\n%d",temp->val); /* printing queue values */
getchar();

}