sql stored procedure for insert

Hi,
Iam creating stored procedure for insert statement but it is giving error that
must declare scalar varialbe empno (i am not understanding) please help me onthis
create procedure proc
(
@empno varchar(50) not null,
@leaveappdate varchar(50) not null,
@leavetype varchar(50) not null,
@balance varchar(50) not null,
@fromdate varchar(50) not null,
@todate varchar(50) not null,
@fromduration varchar(50) not null,
@toduration varchar(50) not null,
@noofdays varchar(50) not null,
@sanctionauthority varchar(50) not null
)
as
insert into CasualRestrictedLeaves values(@empno ,@leaveappdate ,@leavetype varchar(50),@balance ,@fromdate ,@todate ,@fromduration ,@toduration ,@noofdays ,@sanctionauthority );