public static int getX(RSInterface parent, RSInterface child) {
		if (parent == null || parent.children == null || child == null) {
			return -1;
		}
		for (int index = 0; index < parent.children.size(); index++) {
			if (parent.children.get(index) == child.id) {
				return parent.childX.get(index);
			}
		}
		return -1;
	}