How to set incrementer column in SQL Server 2005 -

i have sql server table tbl_slide_master. has 1 column slide_position int. when admin wants add new slide column incremented 1 existing max value of column. , want update field.

for further info included code.

set ansi_nulls on set quoted_identifier on go alter procedure [dbo].[sp_insertnewslide] (     @header_text varchar(25),     @imagename varchar(50),     @img_height int,     @img_width int,     @para_text varchar(520),     @newid int output ) begin tran;     begin try         insert [omstocks].[dbo].[tbl_slide_master]            ([header_text]            ,[imagename]            ,[img_height]            ,[img_width]            ,[para_text]            ,[slide_position]             )           values            (@header_text,@imagename,@img_height,@img_width,@para_text,select max(slide_position)+1)         set @newid= scope_identity()     commit tran;     end try       begin catch     rollback tran;         declare @errmsg nvarchar(4000), @errseverity int;         select @errmsg = error_message(), @errseverity = error_severity();         raiserror(@errmsg, @errseverity, 1);   end catch; 

there 1 error occurred like

msg 1046, level 15, state 1, procedure sp_insertnewslide, line 21
subqueries not allowed in context. scalar expressions allowed.

in values clause have:

select max(slide_position)+1 

this not valid subquery doesn't include table name in query.

the logic incrementing field not clear me, assume want largest value in table:

select max(slide_position)+1 tbl_slide_master 

however, if normal identity field, should declare identity (1,1) field in table creation script , let sql server manage it..