How to test if an option of select is selected?

Question

Hello,
I have a main page (main.jsp) which calls the servlet (MusicAlbum.do) which in turn accesses the database to get the selected kind of music sent by the user.
<%-- main.jsp --%>
<form action="MusicAlbum.do" method="get" >
          <select name="genre" onchange="submit();">
                      <option selected="selected" >(Please select a kind of music)</option>
                      <option>Jazz</option>
                      <option>Classical</option>
                      <option>Country</option>
                      <option>Blues</option>
          </select>
</form>If the selected kind of music contains no items, i.e the listTitles forwarded by the servlet to the main.jsp is null, how do you test in the main page to abtain this message : "Sorry, there are no items in this album." which is displayed below the options?
I've done like this but it doesn't work:
<c:choose>
       <c:when test="${submitted && empty listTitles}">
             <c:out value="Sorry, there are no items in this album!"/>
            <a href="main.jsp">Please choose another genre</a>
       </c:when>
       <c:otherwise>
       </c:otherwise>
</c:choose>Thanks a lot for your help.

Answer 1

I've found the problem with the help of my teacher.
In fact, my way of using the album names (Jazz, Classical, etc) for the options was not correct. I have hard-coded them :
<form action="MusicAlbum.do" method="get" >
          <select name="genre" onchange="submit();">
                      <option selected="selected" >(Please select a kind of music)</option>
                      <option>Jazz</option>
                      <option>Classical</option>
                      <option>Country</option>
                      <option>Blues</option>
          </select>
</form>The right way is to retrieve them from the database via a servlet.
Once this is done, when I click on an item which contains no album titles at all, the message "There are no items in this album" will be displayed.