求高手给一个Metro风格布局

<table border=1 style='width:100%; table-layout:fixed;'><tr><th colspan=2>我是标题</th><th rowspan=2 colspan=2>我是标题</th><th colspan=2>我是标题</th></tr><tr><th rowspan=2  colspan=2>我是标题</th><th>我是标题</th><th>我是标题</th></tr><tr><th colspan=2>我是标题</th><th colspan=2>我是标题</th></tr></table>

$ar = array(  array('1x2', '我是标题'),  array('2x2', '我是标题'),  array('1x2', '我是标题'),  array('2x2', '我是标题'),  array('1x1', '我是标题'),  array('1x1', '我是标题'),  array('1x2', '我是标题'),  array('1x2', '我是标题'),  array('2x2', '我是标题'),  array('2x2', '我是标题'),  array('1x1', '我是标题'),  array('1x1', '我是标题'),  array('1x1', '我是标题'),  array('1x1', '我是标题'),);shuffle($ar);$box = array(  array(1, 1, 1, 1, 1, 1),  array(1, 1, 1, 1, 1, 1),  array(1, 1, 1, 1, 1, 1),);$res = array();foreach($ar as $ind=>$item) {  list($h, $w) = explode('x', $item[0]);  //从左上角开始查找摆放的位置  $flag = 0;  for($y=0; $y<count($box); $y++) {    for($x=0; $x<count($box[$y]); $x++) {      if($box[$y][$x] == 1 && isset($box[$y+$h-1][$x+$w-1]) && $box[$y+$h-1][$x+$w-1] == 1) {        $flag++;        break 2;      }    }  }  if($flag) {    $res[$y][] = array('c' => $w, 'r' => $h, 'v' => $ind);    for($i=0; $i<$h; $i++) {      for($j=0; $j<$w; $j++) {        $box[$y+$i][$x+$j] = 0;      }    }  }}echo "<table border=1 style='width:100%; table-layout:fixed;'>";foreach($res as $row) {  echo '<tr>';  foreach($row as $cell) {    echo "<th colspan=$cell[c] rowspan=$cell[r]>{$ar[$cell['v']][1]}</th>";  }  echo '</tr>';}echo "</table>";