.first_block ul li a{
	background-position:-999px 0;
	filter: progid:dximagetransform.microsoft.alphaimageloader(src='img/menu1.png', sizingmethod='crop');
}
.first_block ul li a:hover,
.first_block ul li a.active{
	background-position:-999px 0;
	filter: progid:dximagetransform.microsoft.alphaimageloader(src='img/active.png', sizingmethod='crop');
}