String function page incorrect?

I'm trying to find the correct function that returns the location of a
substring within a string.  Looking at
http://www.postgresql.org/docs/user/x2731.htm, it gives the Function name as
"textpos" but in the Example column it uses "position".  But neither one
works!

bf2=# select position('high', 'ig');
ERROR:  parser: parse error at or near ","

bf2=# select textpos('high', 'ig');
ERROR:  Function 'textpos(unknown, unknown)' does not existUnable to identify a function that satisfies the given
argumenttypesYou may need to add explicit typecasts
 

bf2=# select textpos(text('high'), text('ig'));
ERROR:  Function 'textpos(text, text)' does not existUnable to identify a function that satisfies the given argument
typesYoumay need to add explicit typecasts
 

???

-Jonathan