var largeImageId = 'l_image';
var smallPath = '/galeria/100x75/';
var largePath = '/galeria/440x330/';

function image_change(obj)
{
    //get parent div id for small image
    var smallParentId = obj.parentNode.id;
    //get small image from attribute
    var smallImageFile = $('#' + smallParentId + ' > img').attr('image');
    //get large image from attribute
    var largeImageFile = $('#' + largeImageId + ' > img').attr('image');
    
    //change large image from small
    $('#' + largeImageId + ' > img').attr('src', largePath + smallImageFile);
    $('#' + largeImageId + ' > img').attr('image', smallImageFile);
    
    //change small image to large
    $('#' + smallParentId + ' > img').attr('src', smallPath + largeImageFile);
    $('#' + smallParentId + ' > img').attr('image', largeImageFile);
}