Server error. LazyStuff.java

LazyStuff.java

package me.hungrybeast.lazystuff;

import org.bukkit.ChatColor;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.bukkit.plugin.java.JavaPlugin;

public class LazyStuff extends JavaPlugin {
	
	public boolean onCommand(Command cmd, String label, CommandSender sender, String[] args)
	{
		if (sender instanceof Player)
		{
			if (label.equalsIgnoreCase("nice"))
			{
			Player player = (Player) sender;
			player.sendMessage(ChatColor.AQUA + "Nice, you sent the Command!");
			}
		}
		return false;
	}
	

}