با سپاس از تمام دوستان مشکل به شکل زیر حل شد .
<!doctype html>
<html>
<head>
<style>
table, th, td {
border: 1px solid black;
}
th{
background-color:#00DBFF;
}
table{border-radius:5px;}
</style>
<meta charset="utf-8">
<title>Untitled Document</title>
</head>
<body>
<table border="1px">
<thead>
<tr>
<th>ID</th>
<th>LastName</th>
<th>FirstName</th>
<th>Age</th>
</tr>
</thead>
<tbody>
<?php
$con=mysqli_connect('localhost','root','','dbtest' );
$q="select * from maya WHERE FirstName='ali'";
$res=mysqli_query($con,$q);
if ($res->num_rows > 0) {
while($row=$res->fetch_assoc()){
echo '<tr>';
echo '<td>'. $row['ID'] . '</td>';
echo '<td>'. $row['LastName'] . '</td>';
echo '<td>'. $row['FirstName'] . '</td>';
echo '<td>'. $row['Age'] . '</td>';
echo '</tr>';
}
}else {
echo "0 results";
}
?>
</tbody>
</table>
</body>
</html>