table合并单元格
新建一张表格。要求表格有四行四列，当中第一行的四列合并，第二行、第三行和第四行的第一列合并
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>table合并单元格</title>
</head>
<body>
<table width="100%" border="1" cellspacing="0" cellpadding="0">
<tr>
<td colspan="4"> </td>
</tr>
<tr>
<td rowspan="3"> </td>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td> </td>
<td> </td>
<td> </td>
</tr>
</table>
</body>
</html>