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
{
	/**
	 * Identify the incoming request category.
	 */
	protected String category;
	/**
	 * Need to store the exception.
	 */
	protected Exception exception = null;
	/**
	 * Get report parameters passed in by URL.
	 */
	protected HashMap parameters = null;
	/**
	 * Whether missing parameters.
	 */
	protected boolean missingParameter = false;
	/**
	 * scalar parameter bean.
	 */
	protected ParameterAttributeBean parameterBean = null;
	/**
	 * Report design name.
	 */
	protected String reportDesignName = null;
	/**
	 * Report document name.
	 */
	protected String reportDocumentName = null;