OnClick Event on Update Field on OrderRel

Maybe something as simple as this would work. On click, do your logic to determine whether you want to release or unrelease, then call SetRels(myChoice);

void SetRels(bool Released)
{
      EpiDataView edvOrderRel = ((EpiDataView)(this.oTrans.EpiDataViews["OrderRel"]));
	// ** Place Event Handling Code Here **
       foreach(var row in edvOrderRel.dataView)
      {
             row["FirmRelease"] = Released;
       }
}