Eszett

[Bruce Pourciau]

How do I get the German letter ß (eszett) to appear? When I type \ss in 
ERT by itself, I get it, but typing the same thing in the middle of a 
German word gives me an error message like this: Undefined control 
sequence.
 ...en Fassungen gewandelt hat. Anschlie\ssend

What am I doing wrong?
Bruce