Run a script when document opens

Thank God for this forum !!!!

I am trying to add a script to a document that will run as soon as it opens.

I have put a form field in the document that states that "This doucment need Javascript enabled to run properly".

When the document opens I want to run a script that hides the form field.

This means if Javascript is enabled the form field will not appear, If javascript is not enabled the form field stays visble and informs the user they must enable it.

I need the solution to be totally encapsulated within the document eg; folder options are not an option as I am sending the doucments out to clients with varying setups.

I have looked at Doc/Open but cannot work out how to get it working for me.

Thanx in advance to anyone who can help

Mark Green