If you reply to a specific post your reply will only appear under it if no one else has added to the thread before you. Posts are added in strict date/time order. You might find using the reply with quote will work better for you if you are concerned about losing the flow of what you are saying.
So if you want to reply to a specific post - then select the "Reply" button on the post it self. If it's a general reply on a thread - then you can just select add reply at the bottom of the thread.
Hope that makes sense.
[snapback]123022[/snapback]
Thanks Pammy I will give it a try, I posted Reply just now when I am replying to you so we'll see how it works thanks again.