Error regarding <ul> tag within a <ul>

I am trying to validate http://bass.kpkammer.com/index.html.

I receive 3 errors  (all the same line 28,34,&40) regarding the unordered list tag (<ul>).
The error states:

   Error         Line 28,             column 7:         document type does not allow element "UL" here; assuming missing "LI" start-tag .
     <ul>

I don't understand why there is an error.  My code reads (line 1 is line 25):

     <ul>
       <li><a href="/index.html">Home</a></li>
       <li><a href="/calendar/index.html">Calendar</a></li>
       <ul>
         <li><a href="/calendar/month/index.html">Monthly Calendars</a></li>
      <li><a href="/calendar/perform.html">Performance Schedule</a></li>
      <li><a href="/calendar/scores.html">Contest Scores</a></li>
       </ul>
       <li><a href="/description/index.html">Description of the Marching Griffins</a></li>
       <ul>
         <li><a href="/description/band.html">The Band</a></li>
      <li><a href="/description/show.html">2007-08 Field Show</a></li>
      <li><a href="/description/courses.html">Course Offerings</a></li>
       </ul>
       <li><a href="/member/index.html">Member Information</a></li>
       <ul>
         <li><a href="/member/itin/index.html">Itineraries</a></li>
      <li><a href="/member/form/index.html">Forms</a></li>
       </ul>
    </ul>

I don't understand what the error is.  Can you help me resolve this?

Kenton Kammer



____________________________________________________ 
 
Kenton P. Kammer 
 
E1:kpkammer@yahoo.com
E2:kenton@kpkammer.com
W1:http://www.kpkammer.com
W2:http://www.icncomputers.com
P: (708)336-4043
F: (775)330-5966
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