[Skypeenglish] Knocking?

[Kay Malmquist]

Hi all,
I was checking out my updated skype and heard a strange noise.  I didn't 
know what it was until I checked out the sounds and discovered that it was 
the knock.  I know who the failed call was from and plan to contact them 
soon, but wondered if a knock was for chatting and the ring was for calls? 
Also is there a way to have a popup come up when you get a call or someone 
wants to chat?  I saw the option to show in windows tray but there didn't 
seem to be any other option.  Thanks again.
Kay