Add hyphen after field I have 2 fields; field_a and field_b.  When field_b is not empty, I need to append a hyphen after field_a.

EX: field_a - field_b

Then, when field_b is empty, it doesn't show the hyphen

EX: field_a

I have been trying THEME_preprocess_field and THEME_field in template.php, but can't get it to work.  This is what I have, but its basically just a copy, but I don't need all the extra stuff, and I need it to only show up on field_a when field_b is not empty.

function THEME_field($variables) {
  $output = '';


  $output .= '&lt;div class="field-itemsuu"' . $variables['content_attributes'] . '&gt;';
  foreach ($variables['items'] as $delta =&gt; $item) {
    $classes = 'field-item ' . ($delta % 2 ? 'odd' : 'even');
    $output .= '&lt;div class="' . $classes . '"' . $variables['item_attributes'][$delta] . '&gt;' . drupal_render($item) . ',' . '&lt;/div&gt;';
  }
  $output .= '&lt;/div&gt;';

  // Render the top-level DIV.
  $output = '&lt;div class="' . $variables['classes'] . '"' . $variables['attributes'] . '&gt;' . $output . '&lt;/div&gt;';

  return $output;
}
You can keep it simple and just add the following to your css 

.field_b:before{
  content:"-";
}


It will only show when there is a value for the b field.