anchor.diff:      {
           wiki = WikiEngine.getInstance( getServletConfig() );
       }
  +
  +    String getVersionText( int ver )
  +    {
  +        return ver > 0 ? ("version "+ver) : "current version";
  +    }
  +
       Category log = Category.getInstance("JSPWiki"); 
       WikiEngine wiki;
   %>
  
positive.code: 
      String pageurl = wiki.encodeName( pagereq );    
  
      String srev1 = request.getParameter("r1");
      String srev2 = request.getParameter("r2");
  
      if( srev1 == null || srev2 == null )
      {
          throw new ServletException("Empty parameters given to Diff.jsp");
      }    
  
      int ver1 = Integer.parseInt( srev1 );
      int ver2 = Integer.parseInt( srev2 );
  
      log.debug("Request for page diff for '"+pagereq+"' from "+request.getRemoteHost()+" by "+request.getRemoteUser()+".  R1="+ver1+", R2="+ver2 );
  
  
negative.code:          if( wiki.pageExists( pagereq ) )
           {
               %>
               Difference between revision <%=versionDescription1%> and <%=versionDescription2%>
               <P>
               <PRE>
  <%=wiki.getDiff( pagereq, ver2, ver1 )%>
  