To pass schemaname as a function parameter

Hi,

I wrote a function in plpgsql, to dispaly the student list.

In a Database all schemas contains studentlist table. so I wrote the function with schemaname as a parameter(text data type). My code is like

CREATE FUNCTION disp_fn(schemaname text) AS $$
BEGIN   SELECT * FROM schemaname.studentlist;
END;
$$ LANGUAGE plpgsql;

In the above function schemaname varaible does not taken.

Is there any way to pass schemaname as argument? Any idea would be much  appreciated.

Thanks in Advance.

Regards

Softlinne