.block_header { margin:0 auto; width:966px; }
#linkdemo1 a{background:url(users1.png) no-repeat; width:115px; height:97px; position:relative; left:35px; top:0px; float:left;}
 a, img {border:none;}
#linkdemo1 a:hover{background:url(users1.png) repeat 130px 98px transparent; width:115px; height:97px;  position:relative; z-index:99}

#linkdemo2 a{background:url(admin1.png) no-repeat; width:115px; height:97px; position:relative; left:185px; top:0px; float:left;}
 a, img {border:none;}
#linkdemo2 a:hover{background:url(admin1.png) repeat 130px 98px transparent; width:115px; height:97px;  position:relative; z-index:99}


#linkdemo3 a{background:url(contact.png) no-repeat; width:115px; height:97px; position:relative; left:346px; top:0px; float:left;}
 a, img {border:none;}
#linkdemo3 a:hover{background:url(contact.png) repeat 130px 98px transparent; width:115px; height:97px;  position:relative; z-index:99}


#linkdemo4 a{background:url(public.png) no-repeat; width:115px; height:97px; position:relative; left:466px; top:0px; float:left;}
 a, img {border:none;}
#linkdemo4 a:hover{background:url(public.png) repeat 130px 98px transparent; width:115px; height:97px;  position:relative; z-index:99}