<html>
<head>
<title>Div example</title>
</head>
<body>
<style type="text/css">
.matrix {
cell-spacing: 0px;
border-spacing: 0px;
border-collapse: collapse;
border: 1px solid #cccccc;
}
.matrix td {
height: 50px; width: 50px;
border: 1px solid #cccccc;
background-color:#00ff00;
}
.matrix td.cell_a {
background-color:#ff0000;
}
.matrix td.cell_b {
background-color:#0000ff;
}
</style>
<table summary="" class="matrix">
<tr>
<td class="cell_a" ></td>
<td class="cell_a" ></td>
<td class="cell_a" ></td>
</tr>
<tr>
<td class="cell_b" ></td>
<td></td>
<td></td>
</tr>
</table>
</body>
</html>