Is there a way to create a login user control that does it's postback using SSL so that the entered username and password are protected?

I need to do this without SSL Encrypting the entire page since this control will be included as part of the master template for the site and only a small percentage of site visitors will actually use the login. Thus it doesn't make sense to SSL the entire website.

In old-style ASP...

I have a login.aspx page where I used login usercontrol in that page and now in master page I have iframe which src points to this login.aspx
now when i want to sigin in the iframe it is refreshing the iframe only I want to reload the whole page.
In the login.aspx I have links for new register,forgot password etc and with help of java Script I managed to refresh them on the content page

I added the below in login.aspx...