V Bao Thu on "How to echo widget in before_title and after_title"

Hello everyone.

I am using Bootstrap to style collapse Widget

This is my code register sidebar

http://pastebin.com/Pp6bqcPc

register_sidebar( array(
		'name' => __( 'Main Sidebar', 'twentytwelve' ),
		'id' => 'sidebar',
		'description' => __( 'Main Sidebar for Destop', 'twentytwelve' ),
		'before_widget' => '
          <aside id="%1$s" class="panel panel-success">
		',
		'after_widget' => '
              </div>
            </div>
          </aside>
		',
		'before_title' => '
            <div id="%1$s" class="panel-heading">
              <h4 class="panel-title">
                <a data-toggle="collapse" data-parent="#accordion" href="#collapseOne">
		',
		'after_title' => '
                </a>
              </h4>
            </div>
            <div id="collapseOne" class="panel-collapse collapse in">
              <div class="panel-body">
		',
	) );

My question : How to echo variable %1$s in before_title and after_title.

I also try, but it doesn't work.

'before_title' => '
            <div id="%1$s" class="panel-heading">
              <h4 class="panel-title">
                <a data-toggle="collapse" data-parent="#accordion" href="#%1$s">
		',
		'after_title' => '
                </a>
              </h4>
            </div>
            <div id="%1$s" class="panel-collapse collapse in">
              <div class="panel-body">
		',

Please tell me how to do that. Thank you very much !