// independently show and hide (independent)
$(document).ready(function() {
  $('div.showHide:eq(0) > dd').hide();  
  $('div.showHide:eq(0) > dt').click(function() {
    $(this).next().slideToggle(100); //OR 'slow' OR 'normal' OR 'fast'
  });
});



//simultaneous showing and hiding (dependent)

$(document).ready(function() {
  $('div.showHide2:eq(0) > dd').hide();
  $('div.showHide2:eq(0) > dt').click(function() {
    $(this).next('dd').slideToggle('fast')
    .siblings('dd:visible').slideUp('fast');
  });
});