$$('#previous-votes .vote').each(function(elm){Event.observe(elm.getElementsByTagName('H3')[0], 'click', handle_poll_click);});

function handle_poll_click(evt)
{
    var elm = Event.element(evt);
   
    var votes = $('previous-votes').getElementsByClassName('vote');
    var cnt   = votes.length;
    
    for(var i=0;i<cnt;i++)
        votes[i].getElementsByTagName('DIV')[0].removeClassName('visible');

    $(elm.parentNode).getElementsByTagName('DIV')[0].addClassName('visible');
}