Bug 136770 Cannot view report document from web viewer
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/utility/ParameterAccessor.java
* 
	 * @param request
	 *            http request
	 * @param name
	 *            parameter name
	 * @param value
	 *            default parameter value
	 * @return new query string with new parameter value
	 */
	public static String getEncodedQueryString( HttpServletRequest request,
			String name, String value )
	{
		String queryString = ""; 
		Enumeration e = request.getParameterNames( );
		Set nullParams = getParameterValues( request, PARAM_ISNULL );
		boolean isFirst = true;
		while ( e.hasMoreElements( ) )
		{
			String paramName = (String) e.nextElement( );
			if ( paramName != null
					&& !paramName.equalsIgnoreCase( PARAM_ISNULL ) )
			{
				String paramValue = getParameter( request, paramName, false );
				if ( nullParams != null
						&& nullParams.remove( toUTFString( paramName ) )
						&& !paramName.equalsIgnoreCase( name ) ) 
				
				
				{
					paramName = urlEncode( paramName, "ISO-8859-1" );