function img(selfimage)
{
    if (image = document.getElementById('img-detail'))
    {
      var originalSource = new String(selfimage.src);
      var re = new RegExp('^(http://.*)/maly(.*)-(.*)\.(jpg|JPG)$');
      var newSource = originalSource.replace(re, '$1/velky$2-$3\.$4');
      image.src = newSource;
    }
}