title: JAR file not Running Properly
body: <p>I have created a runnable jar file that contains the following classes:</p>
  
  <p>Main.class (This contains the main method)</p>
  
  <p>Form.class</p>
  
  <p>WrapLayout.class</p>
  
  <p>The manifest file (Manifest.txt) contains the following:</p>
  
  <pre><code>Main-Class: Main
  </code></pre>
  
  <p>(It has a new line at the end)</p>
  
  <p>I have created the jar file using this command:</p>
  
  <pre><code>jar cfm Organizer.jar Manifest.txt Main.class Form.class WrapLayout.class
  </code></pre>
  
  <p>The jar file is created, but when I run it, the command window opens up for a split second, closes, and nothing else happens. The file is a swing application, and I am running Windows XP on Parallels Desktop for Mac, but I don't think that matters. Does anyone know what's wrong? </p>
  
  <p>EDIT: I tried running the jar file in mac, and I got this error message in the console:</p>
  
  <pre><code>Exception in thread "main"
  java.lang.UnsupportedClassVerionError: Main : Unsupported major.minor version51.0
  </code></pre>