I would like to make my webpages a w3c valid.so i rectifying the errors step by step to be valid , i used html5 doctype, I found an error 

Line 348, Column 81: RDFa Core attribute rel is not allowed on the li element in HTML5 + RDFa 1.1 Lite documents. Consider checking against the HTML5 + RDFa 1.1 schema instead.

so i tried to replaced id instead of rel , w3c valid but the code doesn't work . How to work the below code without using rel?

&lt;script type="text/javascript"&gt;
$(document).ready(function() {
$(".tab_content").hide();
$(".tab_content:first").show(); 
$("ul.tabs li").click(function() {
    $("ul.tabs li").removeClass("active");
    $(this).addClass("active");
    $(".tab_content").hide();
    var activeTab = $(this).attr("rel"); 
    $("#"+activeTab).fadeIn(); 
});
});
&lt;/script&gt; 
&lt;ul class="tabs"&gt;
&lt;li class="active" rel="tab2"&gt;&amp;nbsp;&amp;nbsp;Reviews&amp;nbsp;&amp;nbsp;&lt;/li&gt;&lt;li rel="tab3"&gt;News&lt;/li&gt;&lt;li rel="tab4"&gt;&amp;nbsp;&amp;nbsp;Articles&amp;nbsp;&lt;/li&gt;&lt;/ul&gt;


&lt;div id="tab1" class="tab_content" style="width:326px;"&gt;data&lt;/div&gt;
&lt;div id="tab2" class="tab_content" style="width:326px;"&gt;data tab2&lt;/div&gt; 



Question: Images give 404 after changing default domain
Answer: You will want to run a find-and-replace script across the database to update all URLs to reflect the new domain. Just because you change the WordPress settings doesn't mean the content stored in the database has been updated with the new domain! I've had good luck with the Velvet Blues Update URLs plugin but you can also do this type of find and replace update using phpMyAdmin or other similar database tools.