#navigation a#item1 {background:transparent url(images/header_nav.jpg) 0px 0px no-repeat;}
#navigation a#item2 {background:transparent url(images/header_nav.jpg) -62px 0px no-repeat;}
#navigation a#item3 {background:transparent url(images/header_nav.jpg) -123px -91px no-repeat;}
#navigation a#item4 {background:transparent url(images/header_nav.jpg) -184px 0px no-repeat;}

#navigation a#item1:hover {background-position:0 -91px; z-index:50;}
#navigation a#item2:hover {background-position:-62px -91px; z-index:50;}
#navigation a#item3:hover {background-position:-123px -91px; z-index:50;}
#navigation a#item4:hover {background-position:-184px -91px; z-index:50;}