Re: Release Date vs. Highlight Until Date

Thanks to everyone who responded on this thread.  I did have some time 
to read parts of an old copy of White's "Mastering XSLT" (not the best 
intro I think) over the weekend, and ordered another recommendation.  I 
still don't understand why/when to use for-each and when to use 
apply-templates, but I seem to prefer for-each.  I have restructured the 
XML and implemented a variety of the suggested techniques.  One thing 
I'm still strugling with is how to select the date value for sorting.  
Say I have XML something like the following:
<items>
 <item release="20031212T121212" highlight="20041212T121212" />
</item>

where there could be any number of item elements.  I want to select for 
sort one of the attributes from each item and use that in the sort.  The 
attribute I want is release unless highlight is less than sysdate.  
Right now I am getting sysdate and doing the logic with extensions, but 
I would prefer to avoid this (I know I can get rid of the sysdate 
extension with parameters but I am more concerned about the comparison 
extension).  My C# extension looks like this (I can't even be sure this 
is the right logic - it *seems* to work - but hopefully you get the 
idea).  Thanks in advance to anyone who can convert this to pure XSL.
       public string SortNewsDate( string strSysDate, string 
strHighlightUntilDate, string strReleaseDate )
       {
           DateTime dtResult = DateTime.MinValue;

           try
           {
               if ( strSysDate != null && ! strSysDate.Equals( "" ))
               {
                   if ( strHighlightUntilDate != null && ! 
strHighlightUntilDate.Equals( "" ))
                   {
                       dtResult = DateTime.ParseExact( 
strHighlightUntilDate, SC_DATE_FORMAT, null );
                   }

                   if ( dtResult.CompareTo( DateTime.ParseExact( 
strSysDate, SC_DATE_FORMAT, null )) < 0
                       && strReleaseDate != null && ! 
strReleaseDate.Equals( "" ))
                   {
                       dtResult = DateTime.ParseExact( strReleaseDate, 
SC_DATE_FORMAT, null );
                   }
               }
           }
           catch( Exception ex )
           {
               throw new Exception( ex.Message + strSysDate + " : " + 
strHighlightUntilDate + " : " + strReleaseDate );
           }

           return( dtResult.ToString( SC_DATE_FORMAT ));
       }