#centrar{ 
 position: absolute;
                left: 50%;
                top: 50%;
                width: 992px;
                height: 624px;
                margin-top: -312px;
                margin-left: -496px;
                padding-bottom:0px;
  overflow:hidden;
  vertical-align:top;
}
body{
 background-image:url("images/fondo.jpg");
 background-position:center;
 background-repeat:repeat-x;
 background-color:#0062bb;
 width:100%;
 height:100%
}