[jQuery] Set radio buttons in jQuery Dialog

[pclymer]

I have a 2 radio buttons in a jQuery Dialog :

<table>
   <tr>
      <td><input id="ArriveTriggerIgnition" name="ArriveTrigger"
type="radio" value="ignition"/></td><td>Ignition off at Location</td>
   </tr>
   <tr>
     <td><input id="ArriveTriggerIdle" name="ArriveTrigger"
type="radio" value="idle" /></td><td>Arrive when Idle for</td>
   <tr>
</table>

I am setting the radio button based on another value before opening
the dialog:

 if (triggerIgnition == "True") {
            $("#ArriveTriggerIgnition")[0].checked = true;
        }
        else {
            $("#ArriveTriggerIdle")[0].checked = true;
        }

I have also tried:

      $("#ArriveTriggerIgnition").attr("checked", true); &  $
("#ArriveTriggerIgnition").attr("checked", "checked");

Is there something in the jQuery Dialog that is blocking this or is my
syntax simply wrong? Thanks!