组合框不能将id添加到选项值[关闭]

dropdown box is not adding the $id to the value=/customer when selected and goes to the url. It just shows the /customer page but would like it to show .../customer$id as to load their specific page. Thank you for your help

<select type="text" class="form-control" placeholder="Customer Lookup" onchange="window.location=this.options[this.selectedIndex].value">
<option>Customers</option>
<?php

require ('dbconnect.php');
$result = $con->query("select id, lastname, firstname from customer");

while ($row = $result->fetch_assoc()) {

unset($id, $name);
$id = $row['id'];
$name = $row['lastname'];
$firstname = $row['firstname']; 

echo '<option value="/customer"'.$id.'">'.$name.','.$firstname.'</option>';

}

echo "</select>";
mysqli_close($con);
?> 

Your issue lies here:

echo '<option value="/customer"'.$id.'">'.$name.','.$firstname.'</option>';
                              ^

You're closing off the value attribute with that extra ".

Do this instead.

echo '<option value="/customer'.$id.'">'.$name.','.$firstname.'</option>';