.nav{ border:0px solid #000; width:540px;}
ul,li{ list-style-type:none; margin:0 ; padding:0}
.nav ul li{ float:left; margin-right:5px; text-align:center;}
.nav ul li a{
line-height:25px; 
 display:block; width:175px;
 -moz-background-clip:border;
-moz-background-inline-policy:continuous;
-moz-background-origin:padding;
background:url(http://www.igegolds.com/images/for_nabi1.gif) no-repeat  right top;
display:block;
float:left; overflow:hidden;
}

.nav ul li a:hover{background:url(http://www.igegolds.com/images/for_nabi2.gif) no-repeat right top;
}