Expression cannot be evaluated

[*pointer]

This is the error I get when in the debugger of VC++, but the program compiles fine. When I run it, there is an immediate error and I have to close the program. Any ideas as to why this is happening?

Code:

#include <iostream.h>
#include <stdlib.h>

class BTree_Data{
	private:
		int location, personType;
	public:
		BTree_Data(){ location = 0; personType = 0; }
		~BTree_Data(){}

		BTree_Data *rightChild;
		BTree_Data *leftChild;

		//Methods
		void setLocation(int i) { location = i; } //error here
		int getLocation(void) { return location; } //here too
		void setPersonType(int i) { personType = i; } //and here
		int getPersonType(void) { return personType; } //last one
};

void addChild(BTree_Data root, BTree_Data iterator);
void delChild(BTree_Data root, BTree_Data iterator);
void printTree(BTree_Data root, BTree_Data iterator);

int main(void)
{
	int choice;
	BTree_Data *root = 0, *iterator = 0;
	root->setLocation(0);
	root->setPersonType(0);
	root->rightChild = NULL;
	root->leftChild = NULL;
	iterator = root;
	
	cout << "Menu:\n" <<
			"\t1: Add a child\n" <<
			"\t2: Delete a child\n" <<
			"\t3: Print tree\n" <<
			"\t4: Exit\n\n" <<
			"::>";
	choice = cin.get();

	switch(choice){
		case 1:
			addChild(*root, *iterator);
			break;
		case 2:
			delChild(*root, *iterator);
			break;
		case 3:
			printTree(*root, *iterator);
			break;
		case 4:
			exit(0);
			break;
		default:
			cout << "Invalid input, please try again\n";
			break;
	}

	return 0;
}

void addChild(BTree_Data root, BTree_Data iterator){
	cout << "addChild() Function" << endl;
}

void delChild(BTree_Data root, BTree_Data iterator){
	cout << "delChild() Function" << endl;
}

void printTree(BTree_Data root, BTree_Data iterator){
	cout << "printTree() Function" << endl;
}

[zen]

It's because you're trying to use member functions of objects that don't exist -

BTree_Data *root = 0, *iterator = 0;
root->setLocation(0);
root->setPersonType(0);

If you want to use root->setLocation(); or root->setPersonType(); then root must point at a BTree_Data object.

[*pointer]

How embarassing, I forgot to use new.