MyGrid.SettingsBehavior.AllowSelectByRowClick = true;

This is the trick to make DevExpress' ASPxGridView grids have clickable rows.

function EditButton_Click(s, e) {
   var keys = MyGrid.SettingBehavior.GetSelectedKeysOnPage();
   if (keys.length < 0) {
      alert('no row is selected');
      return;
   }
   var key = keys[0];
   doWhateverIsNext(key);
}