Using Portal Themes

Hi All,

I am new to EP. My question is. I am supposed to develop a Login Page. Now this page can be developed using WebDynPro and also through Portal. I need to set a theme for this Login Page.

Can someone throw some light on how this theme can be set and also how this theme can be used for some other pages.

Plz provide me with some docs or links.

Regards

Nikhil Bansal