Typing german Umlauts:(and other foreign letters)
In German there are 4 special characters, which also have alternative spellings:
(Umlaut is pronounced Umlout)
ä and Ä : A-Umlaut     Alternative:  ae or Ae
ö and Ö : O-Umlaut    Alternative:  oe or Oe 
ü and Ü : U-Umlaut     Alternative:  ue or Ue 
ß            : Scharfes S   Alternative:  ss
to type them in a HTML-document, either type in the Unicode reference or the special HTML name:
Symbol Reference Description                            Alternative 
       (unicode)                                                 (HTML name)
  ä     ä   Small a, dieresis or umlaut mark      ä 
  Ä     Ä   Capital A, dieresis or umlaut mark   Ä 
  ö     ö   Small o, dieresis or umlaut mark       ö 
  Ö     Ö   Capital O, dieresis or umlaut mark   Ö 
  ü     ü   Small u, dieresis or umlaut mark       ü 
  Ü     Ü   Capital U, dieresis or umlaut mark    Ü 
  ß     ß   Small sharp s, German (sz ligature)  ß
These, and many more "foreign" letters can be found at: 
http://vzone.virgin.net/sizzling.jalfrezi/iniframe.htmUnfortunately, although RootsChat accepts these characters directly from my german keyboard, it doesn't accept the  HTML characters. 
I don't know why. Maybe Trystan does, I will pass the question on to him.