#gallery ul li.th1 {background:url(../../images/retro/retro-thmb-01.jpg);}
#gallery ul li.th2 {background:url(../../images/retro/retro-thmb-02.jpg);}
#gallery ul li.th3 {background:url(../../images/retro/retro-thmb-03.jpg);}
#gallery ul li.th4 {background:url(../../images/retro/retro-thmb-04.jpg);}