how to add live chat button code in new update header file

we want to update the wordpress theme in that header.php we want to add live chat button code.
we want to add live chat button code but where to put this code in header file just guide us .
below is the live chat code:

<!– http://www.LiveZilla.net Chat Button Link Code –>

<style type=”text/css”>

div.img img
{float:right;position:fixed;
top:-70px;right:500px;
overflow:hidden;
}

div.img a:hover img
{float:right;position:fixed;
top:0px;right:500px;
overflow:hidden;
}

</style>

<div class=img>

</div>

<!– http://www.LiveZilla.net Chat Button Link Code –>

<!– http://www.LiveZilla.net Tracking Code –>

<div id=”livezilla_tracking” style=”display:none”></div>

<script type=”text/javascript”>var script = document.createElement(“script”);script.type=”text/javascript”;var src = “http://www.comprompt.co.in/livechat/server.php?request=track&output=jcrpt&nse=”+Math.random();setTimeout(“script.src=src;document.getElementById(‘livezilla_tracking’).appendChild(script)”,1);</script>

<!– http://www.LiveZilla.net Tracking Code –>