jquery - Twitter Bootstrap Collapse not toggling correctly -

i have following code:

<div id="container-collapse">     <div class="row">          <button type="button" class="span4 btn" data-toggle="collapse" data-target="#demo1" data-parent="container-collapse">button1</button>          <button type="button" class="span4 btn btn-danger" data-toggle="collapse" data-target="#demo2" data-parent="container-collapse">button2</button>     </div>     <div class="row">           <div id="demo1" class="collapse">foo bar</div>           <div id="demo2" class="collapse">herp derp</div>     </div> </div> 

i cannot life of me these collapse elements toggle, when 1 opens other closes. instead happens if click 1 button , other, both collapse elements remain open. thought having data-parent element help, no... grateful pointers.

what describe want called "collapse" or "accordion" in twitter.bootstrap. see jsfiddle compares solution. code accordion:

<div class="accordion" id="accordion2">     <div class="accordion-group">         <div class="accordion-heading"> <a class="accordion-toggle" data-toggle="collapse" data-parent="#accordion2" href="#collapseone"> show foo bar </a>          </div>         <div id="collapseone" class="accordion-body collapse in">             <div class="accordion-inner">foo bar</div>         </div>     </div>     <div class="accordion-group">         <div class="accordion-heading">            <a class="accordion-toggle" data-toggle="collapse" data-parent="#accordion2" href="#collapsetwo">show herp derp</a>          </div>         <div id="collapsetwo" class="accordion-body collapse">             <div class="accordion-inner">herp derp</div>         </div>     </div> </div> 

to use 2 buttons in 1 row:

<div class="accordion" id="accordion2">     <div class="accordion-group">         <div >             <a class="accordion-toggle btn" data-toggle="collapse" data-parent="#accordion2" href="#collapseone"> show foo bar</a>              <a class="accordion-toggle btn" data-toggle="collapse" data-parent="#accordion2" href="#collapsetwo">show herp derp</a>         </div>         <div id="collapseone" class="accordion-body collapse in">             <div class="accordion-inner">foo bar</div>         </div>     </div>     <div class="accordion-group">         <div id="collapsetwo" class="accordion-body collapse">             <div class="accordion-inner">herp derp</div>         </div>     </div> </div>