[jQuery] How to get parent element and not break a DOM hierarchy

[webarranger]

Hi all!

I am new to jquery. I have a problem to get first parent element
without breaking a hierarchy.

Example:

<div class="ajaxmain">
    <div class="somediv">

    </div>

    <div class="ajaxform">
        <span>Hello World</span>
    </div>
</div>

I'a trying this:
$('span').parents('.ajaxform, .ajaxmain').get(0);  - this is
heirarchically OK, it returns div.ajaxform

but when I'am trying this or change divs order
$('span').parents('.ajaxmain, .ajaxform').get(0); - it returns me
div.ajaxmain

The divs with classes can have different orders. I am working on ajax
form framework based on jquery where the form is send by ajax and
result is set to the nearest ajax div.

Thanks for help.

Michael Zahradnicek