Hvorfor driller applet'er så meget

Jeg har en applet, der bruger nogle billeder på nogle knapper.

HTML:

<applet code="EditorWindow.class" width="600" height="500">
</applet>

Billederne har jeg lagt i samme mappe, men får denne fejl:

java.security.AccessControlException: access denied (java.io.FilePermission Bold16.gif read)
    at java.security.AccessControlContext.checkPermission(Unknown Source)
    at java.security.AccessController.checkPermission(Unknown Source)
    at java.lang.SecurityManager.checkPermission(Unknown Source)
    at java.lang.SecurityManager.checkRead(Unknown Source)
    at sun.awt.SunToolkit.getImageFromHash(Unknown Source)
    at sun.awt.SunToolkit.getImage(Unknown Source)
    at javax.swing.ImageIcon.<init>(Unknown Source)
    at javax.swing.ImageIcon.<init>(Unknown Source)
    at EditorWindow.<init>(EditorWindow.java:20)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at java.lang.Class.newInstance0(Unknown Source)
    at java.lang.Class.newInstance(Unknown Source)
    at sun.applet.AppletPanel.createApplet(Unknown Source)
    at sun.plugin.AppletViewer.createApplet(Unknown Source)
    at sun.applet.AppletPanel.runLoader(Unknown Source)
    at sun.applet.AppletPanel.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
java.security.AccessControlException: access denied (java.io.FilePermission Bold16.gif read)
    at java.security.AccessControlContext.checkPermission(Unknown Source)
    at java.security.AccessController.checkPermission(Unknown Source)
    at java.lang.SecurityManager.checkPermission(Unknown Source)
    at java.lang.SecurityManager.checkRead(Unknown Source)
    at sun.awt.SunToolkit.getImageFromHash(Unknown Source)
    at sun.awt.SunToolkit.getImage(Unknown Source)
    at javax.swing.ImageIcon.<init>(Unknown Source)
    at javax.swing.ImageIcon.<init>(Unknown Source)
    at EditorWindow.<init>(EditorWindow.java:20)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at java.lang.Class.newInstance0(Unknown Source)
    at java.lang.Class.newInstance(Unknown Source)
    at sun.applet.AppletPanel.createApplet(Unknown Source)
    at sun.plugin.AppletViewer.createApplet(Unknown Source)
    at sun.applet.AppletPanel.runLoader(Unknown Source)
    at sun.applet.AppletPanel.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

Sådan ser koden ud:

public class EditorWindow extends JApplet {
   
    private JTextPane tekst = new JTextPane();
    //Tekst formatterings knapper
    private JButton knapbold = new JButton(new ImageIcon("Bold16.gif"));
    private JButton knapitalic = new JButton(new ImageIcon("Italic16.gif"));
    private JButton knapunderline = new JButton(new ImageIcon("Underline16.gif"));

...osv osv osv

Hvad sker der?