#mainBody {
    position: relative;
    width: 612px;
    margin-left: auto;
    margin-right: auto;
    padding: 10px;
    background-color: white;
    color: black;
    border: 1px solid black;
    height: 610px;
    top: 49px;
    font-size: 10pt;
    font-family: Verdana;
    text-align: center; 
    left: 8px;
    overflow: auto;        
}

table#tblEntradaEst td {
   /* border: dotted 1px;*/  /*Los borde de las columnas*/
}

table#tblEntradaEst td.right {
    padding: 2px;
    background-color: #CACACA;
    text-align:right;
}
º   
table#tblEntradaEst td.left {
    padding: 2px;
    text-align:left;
}