ssl issue due to use of https for jquery plugin

Hi,

I am using jquery plugin to display calender control.But it is showing error $ is undefined and alert show only secure content.It is due use of

<script language="javascript" type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js"></script>
<script language="javascript" type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.16/jquery-ui.min.js"></script>

I think.If I am allowing all content is working fine.It also work fine in MOZILA and chrome.
How to fix it.