Queue implementation using array

#include<stdio.h>
#define SIZE 5
void enQueue(int);
void deQueue();
void display();
int items[SIZE+10], front = -1, rear = -1;
int main()
{
    //deQueue is not possible on empty queue
    deQueue();

    //enQueue 5 elements
    enQueue(1);
    enQueue(2);
    enQueue(3);
    enQueue(4);
    enQueue(5);

    //6th element can't be added to queue because queue is full
    enQueue(6);

    display();

    //deQueue removes element entered first i.e. 1
    deQueue();

    //Now we have just 4 elements
    display();

    return 0;

}
void enQueue(int value){
    if((rear-front)+1 >= SIZE)
        printf("\nQueue is Full!!");
    else {
        if(front == -1)
            front = 0;
        rear++;
        items[rear] = value;
        printf("\nInserted -> %d", value);
    }
}
void deQueue(){
    if(front == -1)
        printf("\nQueue is Empty!!");
    else{
        printf("\nDeleted : %d", items[front]);
        front++;
        if(front > rear)
            front = rear = -1;
    }
}
void display(){
    if(rear == -1)
        printf("\nQueue is Empty!!!");
    else{
        int i;
        printf("\nQueue elements are:\n");
        for(i=front; i<=rear; i++)
            printf("%d\t",items[i]);
    }
}