Next and Previous Entries that match condition? Not sure if what I am looking is possible, but basically I have a section ('portfolio').  At the bottom of each entry I have links to the previous and next entry. Simple.  

My trouble is that the body field in my entries is not always populated, and because of this I would like to by-pass these ones in my nav at the bottom of an entry page.

See my code below which is not working, I have a feeling that my logic is not going in the right direction at all with this...

{% set params = craft.entries.section('portfolio') %}

{% set prevEntry = entry.getPrev(params) %}
{% set nextEntry = entry.getNext(params) %}

{% if prevEntry and prevEntry.body | length %}
    {% set image = prevEntry.portfolioImages.first() %}
    &lt;a href="{{ prevEntry.url }}"&gt;Previous&lt;/a&gt;
{% endif %}

{% if nextEntry and nextEntry.body | length %}
    {% set image = nextEntry.portfolioImages.first() %}
    &lt;a href="{{ nextEntry.url }}"&gt;Next&lt;/a&gt;
{% endif %}
You can add the "non-empty body" conditional to your parameters, as follows:

{% set params = craft.entries.section('portfolio').body(':notempty:') %}
{% set previousEntry = entry.getPrev(params) %}
{% set nextEntry = entry.getNext(params) %}
{# …and so forth #}