Package doesn't exist in Netbeans, successful compilation in cmd, why?

Question

I have a requirement to capture photos using system webcam. For this, I'm using webcam capture library. It contained three jar files. I wanted to package every thing including dependency jars in single jar application.

So, I sorted to unpack the dependent jar files place them in the src folder of netbeans project. So, I extracted them. Two of them start with the same package name org, so I extracted and merged them. Important third package starts with com package. I've placed these three directories in src folder of my netbeans project.

Now the problem is that netbeans, says that package doesn't exist. But, the same project when compiled from command line in windows. It compiled and ran successfully, everything was working fine.

But, when I added the problematic library as a jar to the project, it worked fine, only extracting and placing it in src folder causing the problem.

Why is this error occurring and why in netbeans only, how to resolve this problem?

My code:

package screen;
import com.github.sarxos.webcam.*;     **//Error here**
import com.github.sarxos.webcam.log.*;  **// Error here**
import java.io.*;
import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;
public class Util extends TimerTask{
        private String filePath;
        private String type;
        private Timer timer;
        private Webcam webcam;
        public Util(String path,String type){
            this.timer=new Timer("Capture Timer");
            this.filePath=path;
            this.type=type;
            this.webcam=Webcam.getDefault();
        }
    public void capture() throws IOException{
           if(webcam!=null){
                webcam.open();
                BufferedImage image=webcam.getImage();
                Date date=new Date();
                ImageIO.write(image,type,new File(filePath+"_"+date.toString().replace(' ','_').replace(':','-')+"."+type.toLowerCase()));
                webcam.close();
           }
           else{
               webcam=Webcam.getDefault();
           }
    }
        public  void startCapturing(int period){
            this.timer.schedule(this,0,period);
        }
        public void stopCapturing(){
            timer.cancel();
        }
        public void run(){
                try{
                    capture();
                    System.out.println("Doing");
                }catch(Exception e){
                    e.printStackTrace();
                }
        }
        public static void main(String args[]){
            Util u=new Util("n082430_","PNG");
            u.startCapturing(60000);
        }
}