How to I generate a <span> tag

I'm having a problem generating this HTML is my _header.rhtml.

<div class="cssnav"><a href="/" title="Home"><img src='/images/
over.jpg' alt='label'><span>Home</span></a></div>

I know I need to use the link_to and image_tag but I have not been
able to generate the <span>

This is the basic code

<div class="cssnav">
<% if request.path_parameters['controller'] == "home"%>

  :controller => 'home', :action => 'index'
<% end %

link_to(image_tag('image_file_name'), content_tag('span', 'link location'))