Bug 190727 [regression]Default value issue when switch report parameter from textbox to listbox.[0705]
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
sortKeyChooser.setText( CHOICE_NONE );
		sortKeyChooser.addSelectionListener( new SelectionListener( ) {
			public void widgetDefaultSelected( SelectionEvent e )
			{
				
			}
			public void widgetSelected( SelectionEvent e )
			{
				if ( !( (Combo) e.widget ).getText( ).equals( CHOICE_NONE ) )
				{
					sortDirectionLabel.setEnabled( true );
					sortDirectionChooser.setEnabled( true );
					distinct.setEnabled( true );
				}
				else
				{
					sortDirectionLabel.setEnabled( false );
					sortDirectionChooser.setEnabled( false );
					distinct.setEnabled( false );
				}
			}
		} );
		Composite sortDirectionArea = new Composite( sortGroup, SWT.NONE );
		sortDirectionArea.setLayoutData( new GridData( GridData.FILL_HORIZONTAL ) );
		sortDirectionArea.setLayout( new GridLayout( 2, false ) );
		
		sortDirectionLabel = new Label( sortDirectionArea, SWT.NONE );
		sortDirectionLabel.setText( LABEL_SORT_KEY );
		sortDirectionChooser = new Combo( sortDirectionArea, SWT.BORDER );
		sortDirectionChooser.setLayoutData( new GridData( GridData.FILL_HORIZONTAL ) );