No problem.
I think this is because X-cart's Smarty template engine is attempting to parse the {} tags in your JS code. Try wrapping it with {literal}{/literal} tags. Additionally you have used {} to display your script tags, when it should be <>. And finally you have included jQuery, and jQuery is already included in X-cart, and it should only be included once.
So you have not made one, but 3 separate errors! I think you should win a gold star.
Try this code, replacing everything you put after {include file="customer/pop18.html"}:
Code:
<script type="text/javascript">
{literal}
$(document).ready(function(){
$( ".popup_img_yes" ).click(function() {
$( ".popup" ).fadeOut( 1200 );
});
$( ".popup_img_no" ).click(function() {
window.open("http://www.google.com","_self");
});
});
{/literal}
</script>
So you also need to remove this line: {script src='http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js'}{/script}
And I'm not sure about including a .html file like you have here: {include file="customer/pop18.html"}
I would rename that file to pop18.tpl and pull it in with:
{include file="customer/pop18.html"}
But it may be fine, I've never tried to include a .html file before. Leave it that way at first and tell me if it worked!