To change the pl/sql block to get value from user

Question

In this code instead of assigning value to the sid in the block, I want to get the sid from the user.
please help.
Oracle Database 10g Express Edition Release 10.2.0.1.0 - Product
PL/SQL Release 10.2.0.1.0 - Production
CORE 10.2.0.1.0 Production
TNS for 32-bit Windows: Version 10.2.0.1.0 - Production
NLSRTL Version 10.2.0.1.0 - Production
declare
v_sname t1.sname%type;
v_issue_date t3.issue_date%type;
v_book_title t2.book_title%type;
v_book_id t2.book_id%type;
cursor c1 is
select t1.sname, t3.issue_date, t2.book_title, book_id
from t1 join t3
using(sid)
join t2
using(book_id)
where sid=1;
begin
open c1
loop
dbms_output.put_line( v_sname ||' '  || v_issue_date ||' '  || v_book_title || ' ' || v_book_id);
fetch c1 into v_sname, v_issue_date, v_book_title, v_book_id;
exit when c1%notfound;
end loop;
close c1;
end;
Thank you,

Answer 1

Ok, then try running this one:
set serverout on
set verify off
declare
   in_sid  number  := to_number('&1');
begin
   for c1 in
         select username
         from v$session
         where sid=in_sid
   loop
      dbms_output.put_line( c1.username );
   end loop;
end;
GREGS
PL/SQL procedure successfully completed.
When prompted - enter your session SID, or any number (you might not get anything back, but whatever).
Next, I realize you are using SID as something other than ORACLE SID.  So, how about providing some table definitions, and even some sample data?
Again, ALL information would be useful