title: Java Applet work only on my computer?
body: <p>I'm developing a Java applet that show a message box when you visit the site.
  This is my Java code:</p>
  
  <pre><code>import java.applet.Applet;
  import javax.swing.JOptionPane;
  public class JavaRun extends Applet {
      private static final long serialVersionUID = 1L; 
      public void init()
      { 
          JOptionPane.showMessageDialog(null, "hello world!");     
      }
  }
  </code></pre>
  
  <p>This is the html:</p>
  
  <pre><code>&lt;applet width='100' height='100' code='JavaRun' archive='data.jar'&gt;
  &lt;/applet&gt;
  </code></pre>
  
  <p>On my computer (that have the java SDK) it's work, but when I'm using it on my laptop that have only the standard Java, I get these errors:</p>
  
  <pre>
  at sun.plugin2.applet.Applet2ClassLoader.findClass(Unknown Source)
  at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
  at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
  at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
  at java.lang.ClassLoader.loadClass(Unknown Source)
  at sun.plugin2.applet.Plugin2ClassLoader.loadCode(Unknown Source)
  at sun.plugin2.applet.Plugin2Manager.createApplet(Unknown Source)
  at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
  at java.lang.Thread.run(Unknown Source)
  Exception: java.lang.UnsupportedClassVersionError: Micro : Unsupported major.minor version 51.0...
  enter code here
  </pre>