[jQuery] $(this).next() doesn't work

[diego]

Hi all. how can i addClass from the clicked element <li><a> to the
next <li>?
i've tried this

 $('.first li a').bind('click',function()
$(this).next('li').addClass('second');
});
but won't work,

the original code :
<div class="first>
<ul>
<li><a href="#"><img/></a></li>
<li><a href="#"><img/></a></li>
<li><a href="#"><img/></a></li>
<li><a href="#"><img/></a></li>
</ul>
</div>

and clicking on the first $('li a') the output code should be :

<div class="first>
<ul>
<li><a href="#"><img/></a></li>
<li class="second"><a href="#"><img/></a></li>
<li><a href="#"><img/></a></li>
<li><a href="#"><img/></a></li>
</ul>
</div>

any idea ??

Tnx in advance

Diego