title: Trying to show a button only when a Wordpress custom field value is present
body: <p>On a Wordpress site, in a product template, I have a section that shows a custom field value. On the site, the container is hidden by default. A visitor can click a button that slides open the container. The button is just in the template, static.</p>
  
  <p>I am using this to show the value of my custom field: </p>
  
  <pre><code>if ( function_exists('get_custom_field_value') ){ 
      get_custom_field_value('fieldname', true);  
  }
  </code></pre>
  
  <p>So what I'm trying to do is make it so the button only shows up if there is actually a value in the custom field.</p>
  
  <p>I'm a total PHP newb. Any advice?</p>