.l50t0{
position: absolute;
left: 50%;
margin-left: -550px;
top: 0px;
margin-top: 0;
width: 1100px;
height: 100%;
border-style: solid;
border-color: black;
border-width: 0px;
background-color:transparent;
z-index:0;
}

.l0t0 {
position: absolute;
left: 0;
top: 0;
width:10px;
height:10px;
border-style: solid;
border-color:black;
border-width: 0px;
background-color:transparent;
z-index:0;
}