Sold Out Button with text

[brushwoodnursery]

I'm using a product page that has an Add To Cart area at the top and the bottom of the description. At the bottom only, I'm using Back In Stock Notification. When the Sold Out button appears near the top, I want a short string of text to direct the customer to the bottom to sign up if they wish. I found the call for the Sold Out button to appear. It's in functions_general.php around line 1150 but it only calls for the image to display. Can anyone guide me as to how to include some text?

I'm pretty sure this is the place:

    case ($button_check->fields['products_quantity'] <= 0 and SHOW_PRODUCTS_SOLD_OUT_IMAGE == '1'):
      if ($_GET['main_page'] == zen_get_info_page($product_id)) {
        $return_button = zen_image_button(BUTTON_IMAGE_SOLD_OUT, BUTTON_SOLD_OUT_ALT);
      } else {
        $return_button = zen_image_button(BUTTON_IMAGE_SOLD_OUT_SMALL, BUTTON_SOLD_OUT_SMALL_ALT);
      }