cannot make radio buttons sticky

Question

So I managed to make my radio buttons sticky, but what happened with this code was the user can now select more than one option (they are supposed to only be able to select one), and, somehow once you select an option you cannot un-select it. This is my code right now:

 How did you hear about me?<br/>
    <input type="radio" name="response_fb" value="true"
    <?php if (isset($_POST['response_fb']) == 'true') echo ' checked'; ?>>Facebook/online<br>
<input type="radio" name="response_wordofmouth" value="true"
<?php if (isset($_POST['response_wordofmouth']) == 'true') echo ' checked'; ?>>Word of mouth<br>
<input type="radio" name="response_other" value="true"
<?php if (isset($_POST['response_other']) == 'true') echo ' checked'; ?>>Other

Can anyone help? thanks in advance!

Answer 1

The name attr of all your radio buttons needs to be the same. That is how HTML determines that only one of the group can be selected.

EDIT: I think this is more of what you are shooting for

<?php if (isset($_POST['response']) == 'true') echo '$_POST['response'] was checked'; ?>
<input type="radio" name="response" value="facebook">
<input type="radio" name="response" value="word_of_mouth">
<input type="radio" name="response" value="other">

Answer 2

<input type="radio" name="response" value="facebook"
    <?php if (isset($_POST['response']) and $_POST['response'] == 'facebook') echo ' checked'; ?>>Facebook/online<br>
<input type="radio" name="response" value="wordofmouth"
<?php if (isset($_POST['response']) and $_POST['response'] == 'wordofmouth') echo ' checked'; ?>>Word of mouth<br>
<input type="radio" name="response" value="other"
<?php if (isset($_POST['response']) and $_POST['response'] == 'other') echo ' checked'; ?>>Other

U must set same name and different value !