window.addEvent('domready', function() {
    $$('.switch_image', '.switch_image_2').each( function(elmt) {
        elmt.addEvent('click', changeImage.bindWithEvent(elmt))
    });
});

function changeImage(e)
{
    var klass = this.hasClass('switch_image_2') ? 'visible_photo_2' : 'visible_photo';
    $$('.' + klass).each( function(elmt){
        elmt.className = 'hidden_photo';
    });
    
    var Expression = new RegExp("^thumb_img_([1-9_]*)$");
    var matches = Expression.exec(this.id);
    $('big_img_'+matches[1]).className = klass;
    return correctSubmitHandler(e);
}