how to use jquery rounded plugin in liferay theme?

I have developed a theme in liferay 6.1.

• In css I have written border-radius property, which is not working in IE6-to-IE8.
• border-radius is a css3 property which will work on IE9+
• I want to use jquery rounded corners in my theme in order to add border-radius feature to IE 6+ to IE 8 versions.

I don't know where to add jquery rounded corner plugin. I want to use rounded corner for banner in portal_normal.vm file.

Can any one help me in where I need to add this jquery plugin and how to apply border-radius feature in banner of the theme?

Thanks in advance.

Feeling complex at starting after knowing and doing mistakes i felt it was very simple: i followed the below steps to achieve the above jquery rounded functionality in my theme:

1.added the below code in portal_normal.vm file in section

<script type="text/javascript" src="/html/js/jquery/jquery.js"></script>
<script src="$javascript_folder/jquery_roundcorner.js"></script>

2.created the jquery_roundcorner.js file under _diffs/js folder

added the below code: for adding jquery round corner functionality in banner

$(document).ready(function()    {
    $('#banner').corner();
});

3.removed the border-radius property in banner of custom.css under _diffs.