Anyway of closing windows in the portrait mode?

Close the X in the top right corner?!

Seriously, you could be a little bit more verbose.

Well, Instead of close .. there should be an option for Back button using the camera half-press. I hope this is a possibility which can be add as a CSSU update.

Half Press:
Camera open and camera app in focus-> Refocus camera
Camera Close-> Back button

just a suggestion.. just leo jabbering.. :-)

What gonzo said

In the portrait mode, there is no option to select for you to be able to close your window. An option that comes when you tap on the arrow pointing up in the landscape mode.

Which application are you talking about?

I have a feeling it's MicroB, in which case the easiest way of doing it without remapping any of the buttons is to select bookmarks, then select task switcher and finally close the browser window from the task switcher.

Yeah, it is microB that I am talking about. There is no task switcher when I selected bookmark. In any case is there a way to be able to pop up the address bar as in the landscape mode?

if you use auto rotation with CSSU, i suggest you disable "enable rotation" in option-setting of MicroB.
Then when you are in portrait you have the address bar available.

Have you got CSSU installed? I can't remember what the default was. I get the following when I browse my bookmarks:

Is it possible to start a new web page in the portrait mode.