how soon can i dive after landing or prior to take off

You can dive right after landing, but you cannot fly immediately after diving. Depending on the number of dives you do in a short period, you will have to wait different periods. For a single dive on just one day, you need to wait a minimum of 12 hours. For multiple days of diving or multiple dives in a day, you need to wait a minimum of 18 hours. We generally recommend waiting 24 hours just to be conservative.

i totally agree with both of them.....

Do you understand the reasons for the diving/flying rules? If you do, it's easier to remember the rules.

I would recommend a refresher course at your local dive shop.