How to send encrypted value of a textbox from client end

While sending password value from client side to server side i need to encrypt textbox value using javascript and receive that encrypted value in the server side.

Here in the link you'll find one example which will send encrypted value of textbox from client end to server end.
I'm trying to implement the same code, but this doesn't send encrypted textbox value from cilent side to server side. I do google regarding this, but no positive result found till now. Kindly help me to resolve this problem.

Thanks in advance.