Binary tree operations ,inorder ,pre and postorder

#include<stdio.h>
#include<malloc.h>


struct btree

{

        int info;
        struct btree *lchild;
        struct btree *rchild;
};

struct btree * createbt();
void preorder(struct btree *);
void postorder(struct btree *);
void inorder(struct btree *);
int main()

{

        struct btree *root;
        root=NULL;
     	root=createbt();
        printf("\n The preorder traversal \n");
        preorder(root);
        printf("\n The postorder traversal \n");
        postorder(root);
        printf("\n The inorder  traversal \n");
        inorder(root);



}

struct btree * createbt()

{

        struct btree *newnode;
        newnode=NULL;
        int data;
        printf("\n Enter the new data ");
        scanf("%d",&data);

if(data != 999)
        {
                newnode=(struct btree *)malloc(sizeof(struct btree));
                newnode->info=data;
                newnode->lchild=NULL;
                newnode->rchild=NULL;

                printf("\n Enter the left child of %d ",data);
                newnode->lchild=createbt();

                printf("\n Enter the right child of %d",data);
                newnode->rchild=createbt();
        }
        return newnode;

}

        void preorder(struct btree *root)
        {
		 if(root!=NULL)
        {
                printf("%d\n",root->info);
                preorder(root->lchild);
                preorder(root->rchild);
        }

        }

         void postorder(struct btree *root)
        {

        if(root!=NULL)
        {
                postorder(root->lchild);
                postorder(root->rchild);
                printf("%d\n",root->info);

        }
	 }

        void inorder(struct btree *root)
        {

        if(root!=NULL)
        {
                inorder(root->lchild);
                printf("%d\n",root->info);
                inorder(root->rchild);


        }

        }