I want to use some third party themes (like synthetica http://www.javasoft.de/synthetica/themes/) in my swing appliaction. i am using eclipse ide, got the jar file of theme and did the following modification(according to the readme file from the theme) in my code

try 
  {      
   UIManager.setLookAndFeel(new SyntheticaBlackMoonLookAndFeel());
  } 
  catch (Exception e) 
  {
   e.printStackTrace();
  }

but after this modification its showing the following error

 The type de.javasoft.plaf.synthetica.SyntheticaLookAndFeel cannot be resolved. It is indirectly referenced from required .class files

what does this mean? i tried searching on net but cant really find any useful answers

Contents of Readme file:

System Requirements
===================

Java SE 5 (JRE 1.5.0) or above
Synthetica V2.2.0 or above

Integration
===========

1. Ensure that your classpath contains all Synthetica libraries (including
   Synthetica's core library 'synthetica.jar').

2. Enable the Synthetica Look and Feel at startup time in your application:

    import de.javasoft.plaf.synthetica.SyntheticaBlackMoonLookAndFeel;

    try 
    {
      UIManager.setLookAndFeel(new SyntheticaBlackMoonLookAndFeel());
    } 
    catch (Exception e) 
    {
      e.printStackTrace();
    }