Am I entering a world of pain...

...by trying to port a SQL Server application to Postgresql?

I am unable to get a simple function to work. Any ideas as to what is wrong
with it?

create or replace function droptable (varchar(255)) returns void as '
begin
drop table $1;
return;
end;
' language 'plpgsql';

This is what happens when I execute the function:

select droptable('asdfadsfasfd');
WARNING: Error occurred while executing PL/pgSQL function droptable
WARNING: line 2 at SQL statement
ERROR: parser: parse error at or near "$1" at character 13

Regards

AM