HTML - Bootstrap Accordion

gistfile1.html

          <div class="accordion" id="accordion2">
            <div class="accordion-group">
              <div class="accordion-heading">
                <a class="accordion-toggle" data-toggle="collapse" data-parent="#accordion2" href="#collapse1">
                  LABEL 1
                </a>
              </div>
              <div id="collapse1" class="accordion-body collapse in">
                <div class="accordion-inner">
                  
                  CONTENUTO 1
                  
                </div>
              </div>
            </div>
            <div class="accordion-group">
              <div class="accordion-heading">
                <a class="accordion-toggle" data-toggle="collapse" data-parent="#accordion2" href="#collapse2">
                  LABEL 2
                </a>
              </div>
              <div id="collapse2" class="accordion-body collapse">
                <div class="accordion-inner">
                  CONTENUTO 2
                </div>
              </div>
            </div>
            <div class="accordion-group">
              <div class="accordion-heading">
                <a class="accordion-toggle" data-toggle="collapse" data-parent="#accordion2" href="#collapse3">
                  LABEL 3
                </a>
              </div>
              <div id="collapse3" class="accordion-body collapse">
                <div class="accordion-inner">
                  CONTENUTO 3
                </div>
              </div>
            </div>
          </div>