Date Format's setErrorText/setErrorValue

I am trying to use the AW.Formats.Date object's setErrorText to show a blank when I get an error (#ERR). The following code does not work.

var dayFormat= new AW.Formats.Date;
dayFormat.setTextFormat("mmm dd, yyyy");
dayFormat.setErrorText("No Data ");
obj.setCellFormat(dayFormat, 2);

Any ideas what I might be doing wrong here?

The code looks correct - should show "No data" message instead of "#ERR".

??