code: public boolean performOk()
  	{
  		IWorkspaceRunnable wr = new IWorkspaceRunnable()
  		{
  			public void run(IProgressMonitor monitor) throws CoreException
  			{
  				IVdmBreakpoint breakpoint = getBreakpoint();
  				boolean delOnCancel = breakpoint.getMarker().getAttribute(ATTR_DELETE_ON_CANCEL) != null;
  				if (delOnCancel)
  				{
  					// if this breakpoint is being created, remove the "delete on cancel" attribute
  					// and register with the breakpoint manager
  					breakpoint.getMarker().setAttribute(ATTR_DELETE_ON_CANCEL, (String) null);
  					breakpoint.setRegistered(true);
  				}
  				doStore();
  			}
  		};
  		try
  		{
  			ResourcesPlugin.getWorkspace().run(wr, null, 0, null);
  		} catch (CoreException e)
  		{
  			// JDIDebugUIPlugin.statusDialog(e.getStatus());
  			// JDIDebugUIPlugin.log(e);
  		}
  		return super.performOk();
  	}
docs: Store the breakpoint properties.
  
  @see org.eclipse.jface.preference.IPreferencePage#performOk()