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/context/BaseAttributeBean.java
/**
	 * Report title.
	 */
	protected String reportTitle = null;
	/**
	 * Report page number.
	 */
	protected String reportPage = null;
	/**
	 * Current locale.
	 */
	protected Locale locale = null;
	/**
	 * Enable master page content.
	 */
	protected boolean masterPageContent = true;
	/**
	 * In designer context.
	 */
	protected boolean isDesigner = false;
	/**
	 * Bookmark.
	 */
	protected String bookmark = null;
	/**
	 * Report format of the request.
	 */
	
	protected String format = ParameterAccessor.PARAM_FORMAT_HTML;
	/**