Thread: program terminates abruptly

I have this program of a binary search tree which works fine but now what is happening is that i am trying to delete an element 8 which i dont input into the tree. But i have a condition where in if the element is not present it should simply return and tell the user and continue with its execution. But as soon as the delete statement is executed the program terminates saying that trees.exe has encountered some problem and do you want to tell microsoft about this problem. What can be the other error i cant seem to understand?

[insert]

Code:

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

#define FALSE 0
#define TRUE 1

void insert(struct node **root, int data);
void searchdata(struct node	**root, int data);
void delete(struct node **root, int data);
void search(struct node **root, int data, struct node **par, struct node **delnode, int *found);
void inorder(struct node **root);

struct node 
{
	struct node *lchild;
	int data;
	struct node *rchild;
};

int main(void)
{

	struct node *root = NULL;
	int data;
	char ch;

	do
	{
		printf("\n Enter the data\n");
		scanf("%d", &data);
		fflush(stdin);
		insert(&root, data);
		printf("\n Do you want to add more elements\n");
		scanf("\n%c", &ch);
		fflush(stdin);
	}while(ch == 'y' || ch == 'Y');

	printf("\n Before deletion: Inorder\n");
	inorder(&root);

	delete(&root, 8);

	printf("\n After deletion of 8: Inorder\n");
	inorder(&root);

	return 0;
}

void inorder(struct node **root)
{
	if(*root == NULL)
		return;
	else if(*root != NULL)
	{
		inorder(&(*root)->lchild);
		printf("\n %d", (*root)->data);
		inorder(&(*root)->rchild);
	}
}

// delete the node in the bst where the data occurs
void delete(struct node **root, int data)
{
	struct node *parent, *delnode, *delsuc, *x;
	int found;

	if(*root == NULL)
	{
		printf("\n BST is empty you funky crazy fellow");
		return;
	}

	parent = NULL;
	// BST is not empty so search the parent, delnode 
	search(root, data, &parent, &delnode, &found);
	if(found == 0)
	{
		printf("\n Data was not found in the tree");
		return;
	}
	
	if(delnode->lchild != NULL && delnode->rchild != NULL)
	{
		// find the inorder successor of the node
		x = delnode;
		delsuc = delnode->rchild;
		parent = delnode;

		while(delsuc->lchild != NULL)
		{
			parent = delsuc;
			delsuc = delsuc->lchild;
		}

		x->data = delsuc->data;
		delnode = delsuc;
	}

	// node to be deleted has no child
	if(delnode->lchild == NULL && delnode ->rchild == NULL)
	{
		if(parent->lchild == delnode)
			parent->lchild = NULL;
		else if(parent->rchild == delnode)
			parent->rchild = NULL;
		// free the memory
		free(delnode);
	}

	// node to be deleted has only one child - left child
	if(delnode->lchild != NULL && delnode->rchild == NULL)
	{
		// set the parent to point to the left child of the node to be deleted
		if(parent->lchild == delnode)
			parent->lchild = delnode->lchild;
		else if(parent->rchild == delnode)
			parent->rchild = delnode->lchild;

		// free the memory
		free(delnode);
	}

	// node to be deleted has only one child - right child
	if(delnode->lchild == NULL && delnode->rchild != NULL)
	{
		// set the parent to point to the right child of the node to be deleted
		if(parent->lchild == delnode)
			parent->lchild = delnode->rchild;
		else if(parent->rchild == delnode)
			parent->rchild = delnode->rchild;

		// free the memory
		free(delnode);
	}
}

void search(struct node **root, int data, struct node **par, struct node **delnode, int *found)
{
	// check if the data is available at the root
	if((*root)->data == data)
	{
		*delnode = *root;
		*found = TRUE;
	}
	else if ((*root)->data > data)
	{
		*par = *root;
		// go to the left of the root
		search(&(*root)->lchild, data, par, delnode, found);
	}
	else if((*root)->data < data)
	{
		*par = *root;
		// go to the right of the root
		search(&(*root)->rchild, data, par, delnode, found);
	}
}

// search the data in the bst
void searchdata(struct node** root, int data)
{
	if((*root)->data == data)
	{
		printf("\n Data Found in the tree");
		return;
	}
	// search in the right of the root
	else if((*root)->data < data)
	{
		if((*root)->rchild != NULL)
		{
			searchdata(&(*root)->rchild, data);
		}
		else
		{
			printf("\n Data not in the tree");
			return;
		}
	}
	// search in the left of the root
	else if((*root)->data > data)
	{
		if((*root)->lchild != NULL)
		{
		searchdata(&(*root)->lchild, data);
		}
		else
		{
			printf("\n Data not in the tree");
			return;
		}
	}
	else
	{
		printf("\n Data does not exist in the tree");
		return;
	} 
}


void insert(struct node **root, int data)
{
	
	struct node *temp;

	// check if its the first element that i am going to add
	if(*root == NULL)
	{
		*root = (struct node *) malloc(sizeof(struct node));
		(*root)->lchild = NULL;
		(*root)->rchild = NULL;
		(*root)->data = data;
		return;
	}
	// this is not the first element
	// find its correct place in the tree
	// data is larger than root so put in the right
	else
	{
		if((*root)->data < data)
		{
			insert(&((*root)->rchild), data);
		}
	
		else if((*root)->data > data)
		{
			insert(&((*root)->lchild), data);
		}
	}
}