Problem solved !

Assuming that CB 1.2 and Joomla 1.5* are intalled.

Open the Module 'CB Login'. Go to 'HTTPS (encrypted) login, register and lost password ' and you can set what you like from the combo box. I selected 'use https for posting login then same'.

I have used the reCAPTCHA plugin as well, so that a mximum of protection for the inputs is afforded. The page jumps back to the original with whatever settings were slected for SSL