JS and others

Hey Gurus,

Need your advise, thoughts and suggestions.

I had this question on my mind that if we have JS code it is as good as being open to the world.

I was wondering if there is some thing else may be Java, .net, Flash or any other technology that would make it possible to hide the code or make it unreadable.

Basically I was thinking of the following scenario: front end validations,

If we are doing a check for proper date format through javascript, then if the end users right clicks, he has the source.
Is it possible to do the same validation on client side and hide the implementation details from the world??????

The problem is I am writing a web application completely in JS and ajax.

So anybody can download the sourcecode.

Is there any technology whose binaries can only be downloaded however could not be reverse engineered??????