Thank you very much Michael.

Will try your answers.

I had tried NAN, which is incorrect :-)

Hi Brian, NaN was a good guess, but yeah 'undefined' is maybe a bit more universal which would maybe work with any kind of control even non-numeric stuff.

The other possibility was to throw an exception if you try to get the .value and there is no numeric representation of it... But that can be somewhat annoying to deal with as well.

- Michael

Undefined works very well!

I have not observed any problems, so I will post _elastica2 under its topic.

- Brian