#hmenu21 {  
  float: center;  
}  

#hmenu21 a {  
  text-decoration: none;  
  color: #ffffff;  
  background: url(http://torrentsgames.ucoz.ru/menu_a.png) repeat center top;  
  display: block;  
  height: 34px;  
  width: 153px;  
  text-align: center;  
  font: bold 12px/33px tahoma, Times, serif;  
  color: rgb(0, 153, 255);  
}  

#hmenu21 a:hover {  
  background: url(http://torrentsgames.ucoz.ru/menu_b.png) repeat top center;  
  display: block;  
  height: 34px;  
  width: 153px;  
  color: #ffffff;  
  text-align: center;  
  font: bold 12px/33px tahoma, Times, serif;  
  color: rgb(12, 9, 9);  
}

<div id="hmenu21"><a href="http://1x.do.am/board/" >Hidden Object</a></div>  
<div id="hmenu21"><a href="http://1x.do.am/board/" >Simulator</a></div>  
<div id="hmenu21"><a href="http://1x.do.am/board/" >Adventure</a></div>  
<div id="hmenu21"><a href="http://1x.do.am/board/" >Education</a></div>  
<div id="hmenu21"><a href="http://1x.do.am/board/" >Fighting</a></div>  
<div id="hmenu21"><a href="http://1x.do.am/board/" >For Kids</a></div>  
<div id="hmenu21"><a href="http://1x.do.am/board/" >Strategy</a></div>  
<div id="hmenu21"><a href="http://1x.do.am/board/" >Arcade</a></div>  
<div id="hmenu21"><a href="http://1x.do.am/board/" >Shooter</a></div>  
<div id="hmenu21"><a href="http://1x.do.am/board/" >Action</a></div>  
<div id="hmenu21"><a href="http://1x.do.am/board/" >Racing</a></div>  
<div id="hmenu21"><a href="http://1x.do.am/board/" >Sport</a></div>  
<div id="hmenu21"><a href="http://1x.do.am/board/" >Quest</a></div>  
<div id="hmenu21"><a href="http://1x.do.am/board/" >Puzzle</a></div>  
<div id="hmenu21"><a href="http://1x.do.am/board/" >RPG</a></div>