chained selection drop down - php

Question

Im trying to do this: When someone selects any option from the drop down called subject, the sections drop down should show all sections of that subject. The subject drop down works well, fetches all names of subjects but the sections one won't work. Im unable to find the issue. It should fetch the sections from the database WHERE/WHEN name(database column) is equal to the subject chosen. Thanks in advance. My code is below:
my js code
<script type="text/javascript">
function getSection(strURL)
{
alert(strURL);
var req = getXMLHTTP(); // fuction to get xmlhttp object
if (req)
{
req.onreadystatechange = function()
{
if (req.readyState == 4) { //data is retrieved from server
if (req.status == 200) { // which reprents ok status
document.getElementById('sectiondiv').innerHTML=req.responseText;
}
else
{
alert("There was a problem while using XMLHTTP:\n");
}
}
}
req.open("GET", strURL, true); //open url using get method
req.send(null);
}
}
</script>
php code:
<div>
Subject:
<?php
$conn = new mysqli('localhost', '', '', '')
or die ('Cannot connect to db');
$result = $conn->query("select name from class");
echo "<select name='subject' onchange='getSection('findsection.php?subject=>'this.value'";
while ($row = $result->fetch_assoc()) {
unset($id, $name);
$name = $row['name'];
echo '<option value="subject">'.$name.'</option>';
}
echo "</select>";
?>
</div>
<br>
<div id="sectiondiv">
Section:
<select name="select">
</select>
</div>
my findsection.php
<? $subject=intval($_GET[‘subject’]);;
$servername = "localhost";
$username = "";
$password = "";
$dbname = "";
$mysqli = new Mysqli($servername, $username, $password, $dbname) or mysqli_error($mysqli);
$section = $mysqli->query("SELECT section FROM class WHERE name = '$subject'")->fetch_object()->section;
$result=mysql_query($section);?>
<select name="section">
<? while ($row = $result->fetch_assoc()) { ?>
<option value><?=$row['section']?></option>
<? } ?>
</select>

Answer 1

You have incomplete/invalid html
echo "<select name='subject' onchange='getSection('findsection.php?subject=>'this.value'";
Change it to this
echo '<select name="subject" onchange="getSection(\'findsection.php?subject=\' + this.value)">';