Tried Code:
$query = mysql_query('SELECT * FROM course');
while($row = mysql_fetch_assoc($query))
$rows[] = $row;
$prev_name1 = '';
$prev_name2 = '';
echo '<div style="border:1px solid lightgray;float:left;width:100%;overflow:auto;">';
echo '<dl width="50%">';
foreach($rows as $row)
{
echo '<dt style="padding:10px;width:50%;text-align:center;background:black;color:white;">'.($prev_name1 != $row['semester'] ? $row['semester'] : '').'</dt>
<dt style="padding:10px;width:50%;text-align:center;">'.($prev_name2 != $row['channel'] ? $row['channel'] : '').'</dt>
<dd><table border="1" width="50%">
<tr>
<th style="text-align:center;">Course Code</th>
<th style="text-align:center;">Name</th>
th style="text-align:center;">Grade</th>
</tr>
<tr>
<td>'.$row['coursecode'].'</td>
<td>'.$row['course'].'</td>
<td>'.$row['grade'].'</td>
</tr>
</table>
</dd>';
$prev_name1 = $row['semester'];
$prev_name2 = $row['channel'];
}
echo "</dl>\n";
echo "</div>\n";