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.
chart/org.eclipse.birt.chart.ui.extension/src/org/eclipse/birt/chart/ui/swt/composites/TriggerDataComposite.java
Label lblBaseParm = new Label( grpParameters, SWT.NONE );
		{
			GridData gdLBLBaseParm = new GridData( );
			gdLBLBaseParm.horizontalIndent = 2;
			lblBaseParm.setLayoutData( gdLBLBaseParm );
			lblBaseParm.setText( Messages.getString( "TriggerDataComposite.Lbl.CategorySeries" ) ); 
			lblBaseParm.setToolTipText( Messages.getString( "TriggerDataComposite.Tooltip.ParameterCategory" ) ); 
		}
		txtBaseParm = new Text( grpParameters, SWT.BORDER );
		GridData gdTXTBaseParm = new GridData( GridData.FILL_HORIZONTAL );
		gdTXTBaseParm.horizontalSpan = 2;
		txtBaseParm.setLayoutData( gdTXTBaseParm );
		txtBaseParm.setToolTipText( Messages.getString( "TriggerDataComposite.Tooltip.ParameterCategory" ) ); 
		Label lblValueParm = new Label( grpParameters, SWT.NONE );
		{
			GridData gdLBLValueParm = new GridData( );
			gdLBLValueParm.horizontalIndent = 2;
			lblValueParm.setLayoutData( gdLBLValueParm );
			lblValueParm.setText( Messages.getString( "TriggerDataComposite.Lbl.ValueSeries" ) ); 
			lblValueParm.setToolTipText( Messages.getString( "TriggerDataComposite.Tooltip.ParameterValue" ) ); 
		}
		txtValueParm = new Text( grpParameters, SWT.BORDER );
		GridData gdTXTValueParm = new GridData( GridData.FILL_HORIZONTAL );
		gdTXTValueParm.horizontalSpan = 2;
		txtValueParm.setLayoutData( gdTXTValueParm );
		txtValueParm.setToolTipText( Messages.getString( "TriggerDataComposite.Tooltip.ParameterValue" ) ); 
		Label lblSeriesParm = new Label( grpParameters, SWT.NONE );
		{
			GridData gdLBLSeriesParm = new GridData( );
			gdLBLSeriesParm.horizontalIndent = 2;