function create_tell_a_friend_btn(img_src, img_height, img_width, img_border, img_alt, idTag){
  document.write('<a href="http://www.oxygen4energy.com/tell_a_friend.php?curl=' + location.href + '&idTag=' + idTag + '" rel="shadowbox;width=350;height=450">');
  document.write('<img src="' + img_src + '" width="' + img_width + '" height="' + img_height + '" alt="' + img_alt + '" border="' + img_border + '" />');
  document.write('</a>');
}