public boolean addChild(String ID, String parentID) {
		// TODO Auto-generated method stub
		// checks if array has any children
		if (!parentID.equals(id)) {
			//checks if array index 0 is empty
			if (children[0]!=null) {

				return children[0].addChild(ID, parentID);

			} else if(children[1]!=null) {

				return children[1].addChild(ID, parentID);
				//no matching children were found
			} else {
				return false;
			}

		}
		// else statement: a child matching the parent ID was found
		else {
			// checks if array has no children
			if (numofchildren == 0) {
				TreeDataStructure child = new TreeDataStructure(ID, parentID);
				numofchildren++;
				children[0] = child;
				return true;
			}
			// checks if array has 1 child
			else if (numofchildren == 1) {
				TreeDataStructure child = new TreeDataStructure(ID, parentID);
				numofchildren++;
				children[1] = child;
				return true;
			} else {
				return false;
			}
		}

	}