Sorted Doubly Linked List

#include <stdio.h>
#include <stdlib.h>
struct node{
    int data;
    struct node *prev,*next;
} *head = NULL;
struct node *create(int value){
    struct node *newNode = (struct node*) malloc(sizeof(struct node));
    newNode->data = value; newNode->prev = newNode->next = NULL;
    return newNode;
}
void insert(struct node *newNode){
    struct node *help = head;
    if(!head || newNode->data < head->data){ //Front insertion
        if(head){
            newNode->next = head;
            head->prev = newNode;
        }
        head = newNode;
    }
    else{
        while(help->next && newNode->data >= help->data) help = help->next;
        if(!help->next && newNode->data >= help->data){ //Back insertion
            help->next = newNode;
            newNode->prev = help;
        }
        if(newNode->data < help->data){ //Middle insertion
            newNode->next = help;
            newNode->prev = help->prev;
            help->prev->next = newNode;
            help->prev = newNode;
        }
    }
}
void delet(int value){
    struct node *help = head, *target = NULL;
    while(help && help->data != value) help = help->next;
    if(!help) printf("\nData not found.");
    else{
        target = help;
        if(target == head) head = head->next;
        else{
            if(target->prev) target->prev->next = target->next;
            if(target->next) target->next->prev = target->prev;
        }
        free(target);
    }
}
void display(){
    struct node *help = head;
    printf("\nThe list is: ");
    if(!head) printf("Empty.");
    while(help){
        printf("\t%d\t", help->data);
        help = help->next;
    }
}
int main(){
    int choice, n;
    while(1){
        display();
        printf("\n\n1.Insert 2.Delete 3.Exit: ");
        scanf("%d", &choice);
        switch(choice){
            case 1: printf("Enter the value to enter: ");
                    scanf("%d", &n);
                    insert(create(n));
                    break;
            case 2: if(head){
                        printf("Enter the value to delete: ");
                        scanf("%d", &n);
                        delet(n);
                    }break;
            case 3: return 0;
        }
    }
}