Bug 202254 Exception is thrown when category values are null and type of X axis is set to DateTime
chart/org.eclipse.birt.chart.ui.extension/src/org/eclipse/birt/chart/ui/swt/wizard/format/axis/AbstractAxisSubtask.java
catch ( ParseException e1 )
			{
				return null;
			}
		}
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.swt.widgets.Listener#handleEvent(org.eclipse.swt.widgets.Event)
	 */
	public void handleEvent( Event event )
	{
		if ( event.widget.equals( txtTitle ) )
		{
			getAxisForProcessing( ).getTitle( )
					.getCaption( )
					.setValue( (String) event.data );
		}
		else if ( event.widget.equals( txtValue ) )
		{
			DataElement de = getTypedDataElement( txtValue.getText( ) );
			if ( de != null )
			{
				getAxisForProcessing( ).getOrigin( ).setValue( de );
			}
		}
		else if ( event.widget.equals( fdcFont ) )
		{
			getAxisForProcessing( ).getLabel( )