How to access multicolumn function results?

Hi

I've got functions that return a TABLE.

If I call it with constant parameters like:
SELECT * FROM some_fct( 42 );
I get a table with column names as the result as intended.


When I rather call it with the parameter coming from another table I get 
a set of records where I don't know how to access specific columns:
SELECT some_fct( some_id ) FROM some_other_table;

Now I get e.g. the result
( id1, value11, value12, value13 ),
( id1, value14, value15, value16 ),
( id2, value24, value25, value26 ),
...


How can I split this up to look like a normal table or view with the 
column names that are defined in the RETURNS TABLE ( ... ) expression of 
the function.