Adding a message into the message stack

[delia]

Okay, that's really easy and understandable.

But I need a tad more info for my situation. You say that the default is error and I see that's the case when I set this up. But I need the error message to also prevent the user from going forward.

I'm trying to tie an action to the choice of attributes on a product. The buyer has a choice of uploading an image or checking a checkbox that says they will send an image later. As one cannot make either a required field and it is an either/or situation, I think (I hope) I have the php code ready for that. But I need it to act as a required action. Here's the code I have so far:

<?php if(isset($_POST['submit'])) {
 if ((!empty($_POST['id[txt_6]'])) && (!empty($_POST['id[13][21]'])))
{
    $messageStack->add('product_info', 'Please either upload a file or check the box that you will be sending a photo separately.');
}
}
    ?>
<?php if ($messageStack->size('product_info') > 0) echo $messageStack->output('product_info'); ?>

This is actually something I've found that's been asked about often in the forum but I didn't find any instructions of how to make these types of fields required.