Changes in login screen

Hi All.

I have an standalone(no portal) webdynpro app that works with the standard authentication screen of netweaver.

I wanna know if there is possible to change that screen to:

- Limit the length of the login and password fields.

- Add a functionallity to change the password.

If those things are possible i wanna know how to do them.

Thx a lot.

Best regards.

Gregory.