Jaswinder0091 on "Jquery problem"

I am trying to apply a simple toggle effect of jquery in page like
this
http://eightfoldinfotech.com/test/

But i am not able to achieve this in my wordpress page.

http://eightfoldinfotech.com/dumra3/?page_id=21

Here what i did

Header.php

<script language="javascript" type="text/javascript" src="<?php echo get_template_directory_uri(); ?>/js/modernizr.custom.js"></script>
<script  type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>

In page

<script type="text/javascript">// <![CDATA[
jQuery(document).ready(function(){
  $('#one').click(function(){

    $("#explain").slideToggle(500);
  });
});
// ]]></script>

<button class="exams_button" id="one">ENGINEERING ENTRANCE EXAM </button>
<div class="details" id="explain"></div>

And here is my css

.regular
{	float:left;
	width:92%;
	height:auto;
	padding:2% 2%;
	background:#e8e9ea;
	margin:2% 2% 2% 4%;
	display:none;
}