Demo (SpreadSheet) compiled with jdk1.1p -> NumberFormatException thrown

Demos were compiled with jdk1.1p and run in appletviewer. The SpreadSheet
demo threw the following exception on Win95 and Solaris (Sparc):

sun.applet.AppletSecurityException: checkexit
at sun.applet.AppletSecurity.checkExit(AppletSecurity.java:225)
at java.lang.Runtime.exit(Runtime.java)
at java.lang.System.exit(System.java)
at DigSimFrame.SimpleDialogHandler(DigSimFrame.java:416)
at DigSimFrame.action(DigSimFrame.java:634)
at SimpleDialog.action(SimpleDialog.java:116)
at java.awt.Component.handleEvent(Component.java)
at SimpleDialog.handleEvent(SimpleDialog.java:105)
at java.awt.Window.postEvent(Window.java)
at java.awt.Component.postEvent(Component.java)
at java.awt.Component.postEvent(Component.java)
at java.awt.Component.dispatchEvent(Component.java)
at java.awt.EventDispatchThread.run(EventDispatchThread.java)
sun.applet.AppletSecurityException: checkexit
at sun.applet.AppletSecurity.checkExit(AppletSecurity.java:225)
at java.lang.Runtime.exit(Runtime.java)
at java.lang.System.exit(System.java)
at DigSimFrame.SimpleDialogHandler(DigSimFrame.java:416)
at DigSimFrame.action(DigSimFrame.java:634)
at SimpleDialog.action(SimpleDialog.java:116)
at java.awt.Component.handleEvent(Component.java)
at SimpleDialog.handleEvent(SimpleDialog.java:105)
at java.awt.Window.postEvent(Window.java)
at java.awt.Component.postEvent(Component.java)
at java.awt.Component.postEvent(Component.java)
at java.awt.Component.dispatchEvent(Component.java)
at java.awt.EventDispatchThread.run(EventDispatchThread.java)
Exception occurred during event handling:
sun.applet.AppletSecurityException: checkexit
at sun.applet.AppletSecurity.checkExit(AppletSecurity.java:225)
at java.lang.Runtime.exit(Runtime.java)
at java.lang.System.exit(System.java)
at DigSimFrame.SimpleDialogHandler(DigSimFrame.java:416)
at DigSimFrame.action(DigSimFrame.java:634)
at SimpleDialog.action(SimpleDialog.java:116)
at java.awt.Component.handleEvent(Component.java)
at SimpleDialog.handleEvent(SimpleDialog.java:105)
at java.awt.Window.postEvent(Window.java)
at java.awt.Component.postEvent(Component.java)
at java.awt.Component.postEvent(Component.java)
at java.awt.Component.dispatchEvent(Component.java)
at java.awt.EventDispatchThread.run(EventDispatchThread.java)