Jquery accordion not collapse by default

I am using collapse plugin provided by bootstrap which is a jquery simple plugin

However it collapse by default, how to modify so that the collapse item is hidden by default, only when i press the header, then the item collapse and show? Thank you

The document of the plugin, just few line so it only takes one minute

$(document).ready( function () {
$(".collapse").collapse()({
  toggle: false,
  show: false
  });
} );

This is the html:

<div class="accordion-group">
            <div class="alert alert-info" data-toggle="collapse" href="#collapse1" style="margin-bottom:0px;">                     
              Collapsible #1
                  </div>   
          <div id="collapse1" class="accordion-body collapse" style="background-color:#ffffff;">
               content1
           </div>
                           <div class="alert alert-info" data-toggle="collapse" href="#collapse2" style="margin-bottom:0px;">                     
              Collapsible #2
                  </div>   
          <div id="collapse2" class="accordion-body collapse" style="background-color:#ffffff;">
               content2
           </div>