Client Side Encryption

[" Ravi Prakash B.V." <ravibv@xxxxxxxxxxxxxxxx>]

hi friends,
I need ur valuable help.
The client(browser) will connect to the server.
He gets the page.
 He fills the form details and when he submit the form, I need local
encryption has to take place to protect the information filled in the
form. (and also I have to add digital signature while submitting the
form).
The transactions are completely through "https connection". Even though
the transaction is completely secure, I want to do encryption and
signing on client side.  How it is possible?
I will very happy If u provide code or links.

Thanks in advance & Regards,
Ravi Prakash