In this thread user named Pekka gave me an advice to open external sites in a new window and provide a "return to site" link which would call "windows.close()" function. The problem is, that I don't know how to do such a "top bar" or something else containing the link on the site I open. Should I open the external site and write to its source? I know that for example sites providing proxies use such top structures. But how do they do it?
Thanks in advance for your answers, Michael