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
case INDEX_3_TOOGLE_VISABILITY :
				this.slValues.topControl = cmpVisiblity;
				break;
			case INDEX_4_SCRIPT :
				this.slValues.topControl = cmpScript;
				break;
			case INDEX_5_HIGHLIGHT :
				this.slValues.topControl = cmpHighlight;
				break;
			case INDEX_6_CALLBACK :
				this.slValues.topControl = cmpCallback;
				break;
			case INDEX_7_TOOGLE_DATAPOINT :
				this.slValues.topControl = cmpDPVisibility;
				break;
			default :
				this.slValues.topControl = cmpDefault;
				break;
		}
		grpValue.layout( );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.swt.events.SelectionListener#widgetSelected(org.eclipse.swt.events.SelectionEvent)
	 */
	public void widgetSelected( SelectionEvent e )
	{
		if ( e.getSource( ).equals( cmbActionType ) )
		{