DIV/CSS/JAVASCRIPT what 2 use here?

“When user/member visits the site and plans to put some message, for this he clicks the button (reply button), At this moment (…if session is not yet created) i want one Form to appear asking for userid & password (on same page). After entering user id and password & submitting the button session should be created and Still We want to be on same page.”

Can it be done…

I’ve asked my question in flashy way… plz click here.

extracted from rediff forum