Read Only Fields

[Reion]

Can some one find me or make me a script so that when a radio button is selected a certain fields become read only or stop the user from typing in them,
also show a star or colour the fields that i want them to type in.

This is for a page in my order panel which askes the user if they are already a registed user, and if they choose "yes" it sets the fields that only new user need to fill in to read only and sets the required fields to a colour or somthink.

Thanks in advanced to any one who helps.
Ps. Im not that good with js or other codes so i might need helping setting it up.

[Twey]

My script here can do that, with a little modification. I'd need to see the page in question to tell you how to set it up precisely, though.

[Reion]

Well the sites down atm and i had a look at yours ill reply with a link when its up.

Thanks Alot

Its back up now, heres the page http://zxhost.co.uk:2045/order/.

Thanks