MORE HELP,PLEASE

It seems you're asking about how to use switches. Here's how to make a simple door:

1.) You can make an event with a door graphic.
2.) Make it the same level as the hero and make it activate by push key (both of these settings are drop down boxes on the lower left side of the event window).
3.) In the event command box, make a new command that turns activates switch 0001.
4.) Make a new page in the event. On the top left side, there are preconditions for that new page to appear. Check the box for the switch and pick number 0001, same as we used above.
5.) Make the graphic for the new page empty and set it below the hero.

That's your basic door. Same process for chests and such. Once you understand what I've just told you how to do, the program will make a lot more sense.

To make a door require a key, you need to use a conditional branch in the first page of your event. But try this out first and see if you've got it down.

Ok, just wanted to make sure you had all that down. To make the door require a key, you need a conditional branch. Use the condition to check if the key item is in your inventory. Check the box while making the condition to include an handler if the condition is NOT met.

Now that you've made your conditional branch, turn that switch on if the player has a key. Between in the second bracket (your "else" case), have a message like "You need a key to unlock this door" or something. The switch does NOT get turned on in this case.

If you've done that correctly, there should be no trouble. Just make sure you turn the switch on INSIDE the "has a key" bracket. That might be your issue.

A conditional branch is a command on the third page of the list. It does one thing if some condition is met (player has a key) and another if the condition is not met (does not have key).

author=Firehawk11
freakin program! what would a conditional branch be in rpg maker 2000?

Ahh, then I would suggest this:
Scroll to the WAAY bottom to find the 2000 help file.

author=Drakonais
Because if you do it the way NewBlack showed you in the picture, the 2nd page of the event needs to be a closed door. You'll still need to do the switch procedure I walked you though (except on page #3) if you want to have a door that you unlock and is then permanently open.

Drankonais is correct. Sorry.

/me blames old age and bitterness.

Turning on switch 0001 (or whatever switch you prefer) will automatically activate page 2 as long as that same switch is set as a precondition. So if page 1 has the conditional branch, just turn the switch on inside the "has key" bracket and it'll jump to page 2.

Page 2 should look like whatever an open door is in your game, whether that's doors open wide or just empty space.

These guys have a pretty good chest tutorial and you can see the code yourself.

http://rm2k3master.blogspot.com/2010/03/chapter-1-basic-chests-complete-chests.html

Continue to part two to see how to require a key properly. Then, instead of making a chest, simply make it a door.

Sounds like a passibility issue. On the door's page 2 (after it's opened with the key), there's a field that says "Position". You want it to say "Below Hero" to have the player character be able walk on top of it. You could use "Above Hero" to have the player character be able to walk under the event, but that's more "archway" tech. Which might be necessary for the tile right after the door! Depends how things are mapped, and what the passibilities are for the tiles in general.