anchor.diff:              }
           }
   
  +        function disableSummaryFields(){
  +            Element.update("summary-beginning", "Incorrect input")
  +            Element.update("summary-days", "")
  +            Element.update("summary-day-range", "")
  +        }
  +
           function highlightOdd(elt) {
               SC.highlight(elt, {
                   endcolor: "#eeeeee",
  
positive.code:                 </div>
                  <div class="value">
                      <form:input path="period.duration.quantity" size="3" maxlength="3"/>
                      <form:select path="period.duration.unit">
                          <form:options items="${durationUnits}"/>
                      </form:select>
                  </div>
              </div>
              <div class="row even">
                  <div class="label">
                      <form:label path="period.repetitions">Repetitions</form:label>
                  </div>
                  <div class="tip" id="repetitionsText">
                      The number of times the days of this period will occur.
  
negative.code:             </div>
              <div class="row odd" id="summary">
                  <div class="label">Summary</div>
                  <div class="value" id="summaryValue">
                     <span id="summary-beginning"> The configured period will last for </span>
                     <span id="summary-days">1 day</span>
                     <span id="summary-day-range">(day 1)</span>.
              <span id="summary-repetitions">
                  It will have the same events on days <span id="summary-event-days"></span>.
              </span>
  