doing Insert operation from sqlfunction

hai sir,
i have one doubt, that is
can we do insert operation from the sqlfunction?.

when i am doing like this
"ALTER function [dbo].[getInsTime](@id int,@empid int,@empname varchar(20))
returns datetime
as
begin
insert into Employee values(@id,@empid,@empname)
declare @res datetime
set @res=(select instime from insertedtime where id=@id)
return @res
end"

it showing the error like this
"Msg 443, Level 16, State 15, Procedure getInsTime, Line 5
Invalid use of side-effecting or time-dependent operator in 'INSERT' within a function."
please give me the answer sir.

Rajendar@sureit