position(text,text) function

I'm having trouble using the position function, it's a simple built-in function.

It returns the index of a substring within a main string.

But, I just can't get it to work, it always gives this silly parser error.
I've tried it in a variety of ways with variables instead of constants casting 
to text and using it in other contexts, (ie. in functions, not just in a 
select).  What am I doing wrong?  Is this not the correct syntax for a two 
argument function?

test=# select position('hello','el');
ERROR:  parser: parse error at or near ","


Karl Orbell.