Java problems with NetMyThread

[Aeren]

Hi everyone! I encountered 2 problems when trying to make my program.

First, I wrote this as Main:

import java.io.*;
import java.util.*;
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;

public class Main extends Applet {
  public static void main (String args[]) {
//  new Graphics();
  System.out.println("Elindultunk!");
  NetMyThread progi = new NetMyThread( 1, 5000, "F:\1\1.txt", "F:\1\2.txt", "lines", "fast" );
  }
}

And it says: Can't find symbol:NetMyThread(it's another class i wrote)

My second problem is with NetMyThread:
It compiles, but says:
Note: F:\3\NetMyThread.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
I've checked it, and it's because i'm using Vectors. I make a new Vector, then try to add several Strings to it like this:

        String str;
        while( ( str = in.readLine( ) ) != null ) {
          sourceElements.add( new String( str ) );
        }

where in is an opened file.
Anyone knows why this is a problem?
Thanks!!!

Aeren

Added after 58 minutes:

Second problem is solved. The vector should have a type(String by my case)
Vector<String> abc = new Vector<String>();