请教一个简单的存储过程！！！ 解决问题马上送分！！！

[King6860]

想传递一个数据库表的名称，然后返回该表的记录行数？？？

create proc CountRecord
@rtVal int output,
@tableName varchar(300)
as
.....

[zjcxc]

create proc CountRecord
@rtVal int output,
@tableName varchar(300)
as
declare @s nvarchar(4000)
set @s='select @rtVal=count(*) from ['+@tableName+']'
exec sp_executesql @s,N'@rtVal int output',@rtVal out

[yesterday2000]

CREATE PROCEDURE tbrows(@tbname varchar (200))

as
begin
select a.rows from sysindexes a,sysobjects b where a.id=b.id and b.name=@tbname
end


exec tbrows 'a'

[King6860]

N'@rtVal int output'

这句 是什么意思？？？