Bug 201042 [Accessibility]Chart scritp should not add by auto when click the down in keyboard[17]
Description: Chart scritp should not add by auto when click the down in keyboard[0704] Step: 1. New a chart and switch to script view. 2. Let the point on the script function selection. 3. Click the down on keyboard. Actual result: A function will add by auto. Expected result: Customer can not select the function under the second function by keyboard, and it should not be added by auto.
UI/org.eclipse.birt.report.designer.ui.editors.schematic/src/org/eclipse/birt/report/designer/internal/ui/editors/script/JSEditor.java
Object model = getModel( );
		if ( model != null )
		{
			cmbExpList.setVisible( true );
			cmbSubFunctions.setVisible( true );
			setComboViewerInput( model );
		}
		else
		{
			setComboViewerInput( Messages.getString( "JSEditor.Input.trial" ) ); 
		}
		cmbExprListViewer.addSelectionChangedListener( palettePage.getSupport( ) );
		cmbExprListViewer.addSelectionChangedListener( new ISelectionChangedListener( ) {
			/**
			 * selectionChanged( event) - This listener implementation is
			 * invoked when an item in the combo box is selected, - It saves the
			 * current editor contents. - Updates the editor content with the
			 * expression corresponding to the selected method name or
			 * expression. name.
			 */
			public void selectionChanged( SelectionChangedEvent event )
			{
				ISelection selection = event.getSelection( );
				if ( selection != null )
				{
					Object[] sel = ( (IStructuredSelection) selection ).toArray( );
					if ( sel.length == 1 )
					{
						if ( sel[0] instanceof IPropertyDefn )