how to use vector icon in header

Hi everyone,

I am using Intel's app framework. As you know it has header component.

<header><a id="backButton" class="button backButton">Back...</a><h1>Custom Header</h1></header>

I want to remove back button and put an icon.

<div class="widget-container content-area horiz-area wrapping-col left with-back"><div class="icon new"></div>
                        </div>

This doesn't work. It shows nothing. What is problem with my code?

Thanks.