Binary Search Tree - BST implementation

Binary Search Tree - BST implementation
	#include<stdio.h>
	#include<stdlib.h>
	typedef struct tree
	{
	int number;
	struct tree *leftChild;
	struct tree *rightChild;
	} node;
	node *root=NULL;
	void insertNode(int value);
	void searchOnTree(int value);
	void preOrderPrint(node *rootNode);
	void inOrderPrint(node *rootNode);
	void postOrderPrint(node *rootNode);
	int main()
	{
	insertNode(45);
	insertNode(54);
	insertNode(40);
	insertNode(49);
	insertNode(38);
	insertNode(70);
	insertNode(30);
	insertNode(39);
	insertNode(41);
	insertNode(45);
	insertNode(44);
	printf("\nPre-Order Tree printing:\n");
	preOrderPrint(root);
	puts("");
	printf("\nIn-Order Tree printing:\n");
	inOrderPrint(root);
	puts("");
	printf("\nPost-Order Tree printing:\n");
	postOrderPrint(root);
	puts("");
	searchOnTree(70);
	return 0;
	}
	void insertNode(int value)
	{
	node *tempNode;
	node *currentNode;
	node *parentNode;
	tempNode = (node *) malloc(sizeof(node));
	tempNode->number = value;
	tempNode->leftChild = NULL;
	tempNode->rightChild = NULL;
	//For the very first call
	if(root==NULL)
	{
	root = tempNode;
	}
	else
	{
	currentNode = root;
	parentNode = NULL;
	while(1)
	{
	parentNode = currentNode;
	if(value <= parentNode->number)
	{
	currentNode = currentNode->leftChild;
	if(currentNode==NULL)
	{
	parentNode->leftChild = tempNode;
	return;
	}
	}
	else
	{
	currentNode = currentNode->rightChild;
	if(currentNode==NULL)
	{
	parentNode->rightChild = tempNode;
	return;
	}
	}
	}
	}
	}
	void searchOnTree(int value)
	{
	node *currentNode = root;
	int flag = 0;
	while(1)
	{
	if(value == currentNode->number)
	{
	flag = 1;
	break;
	}
	else if(value<=currentNode->number)
	currentNode = currentNode->leftChild;
	else
	currentNode = currentNode->rightChild;
	if(currentNode==NULL)
	break;
	}
	if(flag==1)
	printf("\n%d is found on Tree.\n\n", currentNode->number);
	else
	printf("\n%d is not found on Tree.\n\n", value);
	}
	void preOrderPrint(node *rootNode)
	{
	if(rootNode==NULL)
	return;
	printf("%d ", rootNode->number);
	preOrderPrint(rootNode->leftChild);
	preOrderPrint(rootNode->rightChild);
	}
	void inOrderPrint(node *rootNode)
	{
	if(rootNode==NULL)
	return;
	inOrderPrint(rootNode->leftChild);
	printf("%d ", rootNode->number);
	inOrderPrint(rootNode->rightChild);
	}
	void postOrderPrint(node *rootNode)
	{
	if(rootNode==NULL)
	return;
	postOrderPrint(rootNode->leftChild);
	postOrderPrint(rootNode->rightChild);
	printf("%d ", rootNode->number);
	}