Hi guys,
i need some an example how to wrtie a node, wich is subscribing and publishing at the same time.
I want to publish a message when i got i message, beacuse of that i try to publish in the Callback function, but it doesn't work.


My code is following:

void pointCallback(const nxt_msgs::Range  &msg)
{
	  sensor_msgs::LaserScan pub;
	  ros::NodeHandle r;
	  ros::Publisher laser_scan_pub = r.advertise<sensor_msgs::LaserScan>("laser_scan", 50);
	  laser_scan_pub.publish(pub);
}
int main(int argc, char **argv)
{

  ros::init(argc, argv, "range_to_laser");
  ros::NodeHandle n;
  ros::Subscriber sub = n.subscribe("point_cloud", 50, pointCallback);
  ros::spin();

  return 0;
}
Greetings,
Bünyamin