How to iterate through ul list using Javascript?

Question

I have the following HTML page (page is simplified here as it is a sample of the real one):

Answer 1

I know you can't use jQuery for this, but I thought I'd supply a solution for others that may be able to:

$(function(){
    $("li a").click(function(){
        $(this).parent().siblings().each(function(){
            $(this).find("a").css({'color':'blue','background-color':'white'});    
        });
        $(this).css({'color':'white','background-color':'black'});    
        return false;
    });
});