Notice: Undefined index: und in include() I'm having an issue with an undefined index I really could use some help with.

This is the error I get:

Notice: Undefined index: und in include() (line 15)

This is what my line 15 looks like:

&lt;div class="House_Header_coupon_link"&gt;
  &lt;a href="
      &lt;?php print $node-&gt;field_house_coupon_link['und'][0]['url']; ?&gt;
    " style="color:#
      &lt;?php print $node-&gt;field_house_coupon_link_hex_code['und'][0]['safe_value']; ?&gt;
    "&gt;
      &lt;?php print $node-&gt;field_house_coupon_link['und'][0]['title']; ?&gt;
  &lt;/a&gt;
&lt;/div&gt;


I know the error is happening because sometime the field is not given a value and allowed to be blank. I'm using Drupal 7.23 and I've tried using the isset method mentioned elsewhere on this site but it's not working and I'm out of ideas

Thanks!
Before assigning the values to the field directly you must check if it contains any value or not otherwise you will get the notice like above, try to check the value something like below (the below code is for reference only, you can modify it as per your requirement):

&lt;div class="House_Header_coupon_link"&gt;&lt;a href="&lt;?php
print isset($node-&gt;field_house_coupon_link[LANGUAGE_NONE]) ? $node-&gt;field_house_coupon_link[LANGUAGE_NONE][0]['url'] : ""; ?&gt;"
style="color:#&lt;?php print isset($node-&gt;field_house_coupon_link_hex_code[LANGUAGE_NONE]) ? $node-&gt;field_house_coupon_link_hex_code['und'][0]['safe_value'] : ""; ?&gt;"&gt;
&lt;?php print isset($node-&gt;field_house_coupon_link[LANGUAGE_NONE]) ? $node-&gt;field_house_coupon_link['und'][0]['title'] : ""; ?&gt;&lt;/a&gt;&lt;/div&gt;


Also it is recommended to use LANGUAGE_NONE instead of und: The language code used when no language is explicitly assigned. Defined by ISO639-2 for "Undetermined".