Failed to load resource: the server responded with a status of 404 (Not Found)

Your files are not under the jsp folder that's why it is not found. You have to go back again 1 folder Try this:

<script src="../../Jquery/prettify.js"></script>

Note the failing URL:

Failed ... http://localhost:8080/RetailSmart/jsp/Jquery/jquery.multiselect.css

Now examine one of your links:

<link href="../Jquery/jquery.multiselect.css" rel="stylesheet"/>

The "../" is shorthand for "The containing directory", or "Up one directory". This is a relative URL. At a guess, you have a file in /jsp/<somefolder>/ which contains the <link /> and <style /> elements.

I recommend using an absolute URL:

<link href="/RetailSmart/Jquery/jquery.multiselect.css" rel="stylesheet"/>

The reason for using an absolute url is that I'm guessing the links are contained in some common file. If you attempt to correct your relative pathing by adding a second "../", you may break any files contained in /jsp.