Possible Duplicate:
Can I change all my links to just //?
I’ve learnt that I can reference CSS and JavaScript by using the “//domain/path” format rather than being specific about whether the resource should be loaded over HTTP or HTTPS. Examples:
<link href="//ajax.googleapis.com/ajax/libs/jqueryui/1/themes/base/jquery-ui.css" rel="stylesheet" type="text/css" />
<script src="//ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
The browser then loads the resources using the same protocol (schema) as the current page.
Is this supported in all browsers, and if not, which browsers don’t support it?
Yes, but IE 6-7 will download stylesheets twice with this method. Apart from that it works in all common browsers. See Can I change all my http:// links to just //?, Paul Irish – The protocol relative URL.