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
{
			ParameterDefinition  parameterObj = (ParameterDefinition ) iter
					.next( );
			String paramName = parameterObj.getName( );
			Object paramValueObj = this.getParamValueObject( request,
					parameterObj );
			if ( paramValueObj == null )
				paramValueObj = getReportService( ).getParameterDefaultValue(
						design, parameterObj.getName( ), options );
			params.put( paramName, paramValueObj );
		}
		return params;
	}
	protected Object getParamValueObject( HttpServletRequest request,
			ParameterDefinition  parameterObj ) throws ReportServiceException
	{
		String paramName = parameterObj.getName( );
		String format = parameterObj.getDisplayFormat( );
		if ( ParameterAccessor.isReportParameterExist( request, paramName ) )
		{
			ReportParameterConverter converter = new ReportParameterConverter(
					format, locale );
			
			String paramValue = ParameterAccessor.getReportParameter( request,
					paramName, null );
			return converter.parse( paramValue, parameterObj.getDataType( ) );
		}
		return null;
	}
}