How to add a custom sort function to the jquery grid?
<p>I have a table built using JQuery Grid containing 3 columns (name, date, value). 'date' and 'value' columns can have null or 'NA' values. So when I use the below code as part of jqGrid function it works for the 'name' but not for 'date' and 'value' :</p>

<pre><code>    colModel: [
                {name: "name", sortable: true},
                {name: "date", sortable: true},
                {name: "value", sortable: true}
            ],
</code></pre>

<p>How can I get the sorting worked for date and value columns. How should I add the custom sorting to this ?</p>