Javascript in forms

Hi folks:

We're working on a control system for a control panel.

We need a browser that can use some sort of scripting language in forms 
- javascript would be ideal.

With javascript, we would need event support (onload, onfocus, etc) and 
at least partial DOM support so that we could change the values in one 
field based on user input in another field.

We also need the ability to copy information from one row of the form to 
another.

If any of the devs are interested in taking this on, my company is 
willing to sponsor this work (provided, of course, we can come to 
mutually agreeable terms.  :-) )

We can provide detailed information of our needs - in fact I can provide 
all of the javascript we need to run.

Thanks,

--Yan