Bug 153412 Change parameter type will cause preview fail
Description: Change parameter type will cause preview fail Steps to reproduce: 1. New a report paramter, string, text-box, default value is abc. 2. Drag the parameter to Layout and preview. 3. Change the parameter's type to integer, list-box, add a value 1 4. Preview Expected result: No errors. Actual result: The value "abc" is invalid with the type "integer".
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/context/ViewerAttributeBean.java
}
	/**
	 * Parse report object and get the parameter default values
	 * 
	 * @param design
	 *            IViewerReportDesignHandle
	 * @param paramName
	 *            String
	 * @param options
	 *            InputOptionsF
	 * 
	 * @return String
	 */
	protected String getParameterDefaultValues(
			IViewerReportDesignHandle design, String paramName,
			InputOptions options ) throws ReportServiceException
	{
		if ( design == null )
			return null;
		String defalutValue = null;
		Object defaultValueObj = null;
		
		try
		{
			defaultValueObj = this.getReportService( )
					.getParameterDefaultValue( design, paramName, options );
		}
		catch ( ReportServiceException e )
		{
			e.printStackTrace( );