Bug 140534 [Smoke]Can't changed the value of parameter use show report parameter
Details: [Smoke]Can't changed the value of parameter use show report parameter Step: 1. New a parameter. 2. Change display type to list box. 3. Insert some value into selection value and set the first value to default value. 4. Drop the parameter inro layout 5. Preview and press show report parameter, change the value and press OK. Actual result: The value can't be changed.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/presentation/aggregation/parameter/ScalarParameterFragment.java
this.parameter = parameter;
	}
	/**
	 * Get report parameters from engine.
	 * 
	 * @param request
	 *            incoming http request
	 * @param response
	 *            http response
	 * @return target jsp pages
	 * @exception ServletException
	 * @exception IOException
	 */
	protected void doService( HttpServletRequest request,
			HttpServletResponse response ) throws ServletException, IOException
	{
		ViewerAttributeBean attrBean = ( ViewerAttributeBean ) request
				.getAttribute( "attributeBean" ); 
		assert attrBean != null;
		assert parameter != null;
		ScalarParameterBean parameterBean = new ScalarParameterBean( parameter );
		attrBean.setParameterBean( parameterBean );
		String reportDesignName = ParameterAccessor.getReport( request );
		IViewerReportDesignHandle designHandle = new BirtViewerReportDesignHandle(
				null, reportDesignName );
		Locale locale = attrBean.getLocale( );
		boolean isDesigner = attrBean.isDesigner( );
		try
		{
			prepareParameterBean( designHandle, getReportService( ),