i try to use SLF4J for logging. i try something like this:

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import util.HibernateUtil;
public class Main {
	public static void main(String[] args) {
		Toolbox tool = new Toolbox();
class Toolbox {
	Logger logger = LoggerFactory.getLogger(this.getClass().getName());
	public void helloWorld() {
		logger.debug("Temperature set to {}. Old temperature was {}.", 1,2);
		logger.info("Hello World");

when i run in the debug mode, it writes "Hello world" string to the console but it doesn't write the debug string.
i do something wrong?

Are you sure you have used the combination of slf4j-api.jar+slf4j-simple.jar correctly ??