Insert Data in a table having composite primary key???

Hi All,Here is my scenario.I have two tables T1 (Sid int not null, Pid int not null) & T2(Sid int, Pid int). T1 has composite primary key on (sid, pid)... Now I want to insert data from T2 to T1 making sure the data I am inserting in T1 does not exists there... Ofcourse If it exists it will fails due to composite primary key violation. However I don't want it to fail. I want to make sure before hand only when I insert data.So basically, I want to check that the data in T2 table doesn't exist in T1 table first and if not then only insert it in table T1. OR insert only that data which doesn't exist in T1.Thanks in advance for the help.

Check this
create
table t1 (Sid int not null, Pid int not null) create
table T2(Sid int, Pid int) insert
t1 select 1,1insert
t1 select 2,2insert
t1 select 3,3insert t1 select 4,6 insert
t2 select 4,5insert
t2 select 1,1insert
t2 select 2,2insert
t2 select 4,4
-- Method 1insert
into t1 select *From t2 a where
not exists(select * from t1 b where a.sid=b.sid and a.pid=b.pid)--Method 2
insert
into t1 select a.*From t2 a left outer join t1 b
on a.sid=b.sid and a.pid=b.pid where
b.sid is null and b.pid is null