if statement to call custom field in WordPress

[dangermoose]

Hi all,

 

I've been struggling to get an if statement to work. I'm new to PHP so bear with me!

 

I have an events listing page where I pull a value from a custom field to display a 'buy tickets' button. I can get the button to display and it works well but what I need to do is customise the code so if there is no ID present, then a piece of text displays. Any pointers appreciated.

 

This is one method Im using for custom fields which works well - the if statement works here also.

<div>
      <p><strong>Location:</strong>
        <?php $event_location = get_post_meta($post->ID, 'Event_Location', true);
			if ($event_location) {
			?>
        <?php echo $event_location; ?>
        <?php } else { ?>
      <p>No Location Available.</p>
      <?php } ?>
      </p>
    </div>

 

This code pulls in the buy tickets button but I cant figure out how to create an if statement with it! grrrr...

 

 <div>
      <p>
    <?php
 $values = get_post_custom_values('Product_ID');
echo get_button_code_for_product($values[0]);
?>
      </p>
    </div>

 

I would like it to look for the ID and if it can't find it then displays ' No Product ID' or some such text.