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
request, parameterBean, parameter, locale, isDesigner );
			
			prepareParameterBean( request, getReportService( ), parameterBean,
					locale );
		}
		catch ( ReportServiceException e )
		{
			
			e.printStackTrace( );
		}
	}
	/**
	 * Override implementation of doPostService.
	 */
	protected String doPostService( HttpServletRequest request,
			HttpServletResponse response ) throws ServletException, IOException
	{
		String className = getClass( ).getName( ).substring(
				getClass( ).getName( ).lastIndexOf( '.' ) + 1 );
		return JSPRootPath + "/pages/parameter/" + className + ".jsp"; 
	}
	public static void prepareParameterBean( IViewerReportDesignHandle designHandle,
			IViewerReportService service, HttpServletRequest request,
			ScalarParameterBean parameterBean, ParameterDefinition parameter,
			Locale locale, boolean isDesigner ) throws ReportServiceException
	{
		
		String displayName = parameter.getPromptText( );
		displayName = ( displayName == null || displayName.length( ) <= 0 ) ? parameter
				.getDisplayName( )