Form keeps selecting multiple radio buttons - php

Question

I have a feeling there is a simple solution to this problem but I can't seem to figure it out.
I'm using a mix of jQuery, PHP and HTML to generate this dynamic form of mine.
Each result SQL finds will be passed into the form, it will display a person along with a radio button. So if there are 3 returned results in the DB, the form will generate 3 people and one of them will have the radio button already checked. My problem is, I only want to be able to select 1 of the 3 radio buttons generated. It keeps multi selecting and I don't know what's causing it or how to stop/fix it.
Example:
Note - showing snipet to illustrate my point
<?php
$group_query = mysqli_query($conn,"SELECT * FROM Groups WHERE gp_ID = '26'")
or die("Error: ".mysqli_error($conn));
?>
<form action="#" class="form-horizontal" method="post">
<?php
$counter = 1;
$passenger_query = mysqli_query($conn,"SELECT * FROM Customers AS C
WHERE C.gp_ID = '".$group_Results['gp_ID']."'")
or die("Error: ".mysqli_error($conn));
while($passenger_Results = mysqli_fetch_array($passenger_query)){
?>
<input type="radio"
class="the_Leader"
name="the_Leader_<?php echo $counter; ?>"
value="<?php echo $passenger_Results['customer_ID'] ?>"
<?php echo $passenger_Results['customer_ID'] == $group_Results['leader_ID'] ? 'checked' : ''; ?>
/>
<?php
echo $passenger_Results['name'];
$counter++;
}//end while loop
?>
</form>
tl;dr dynamic form generated using PHP/MySQL, one of the results is already checked. Want to be able to change it but form multi selects radio buttons.

Answer 1

You are assigning different name= attributes to the buttons when you write name="the_Leader_<?php echo $counter; ?>". To be in a button group, all buttons must have the same name.
You want the names to be the same and the values to be different; the latter lets you know which button was clicked when the form is submitted.