windeu -please help!-

I'm new to doom editing, and I would like to know a few things about making levels in windeu. windeu is the best editor I could get to work on my XP machine, everything else crashes. Anyways, I need help with making sectors and changing skies. When I try to make a sector inside a sector for platforms, shadows, etc, it looks fine in the game, but the player can't enter the sector. I got the linedefs set to 2-sided and passable, but the player still can't enter the sector. It's like there's an invisible wall. Can someone tell me step by step how to make sectors within sectors with windeu? Also, I can't figure out how to use different textures for skies. In windeu, when you try to pick a texture for a sector ceiling, the only sky texture listed is "f_sky1". I can only pick the other sky textures for linedefs. I opened up the original doom 2 maps, and they all use "f_sky1" for the sky in windeu, but when you play the levels, they have different textures for skies. Can someone tell me what I'm doing wrong?

Here are some tips:

- Skies: F_SKY1 is the default sky "placeholder" -- if a sector uses F_SKY1 as the ceiling, it will be drawn as a sky. The actual sky texture is dependent on which level your level is replacing (for example, in Ultimate Doom, all E1 levels use the gray sky, all E3 levels use the red sky, etc.) So, if you want your level to use the Hell Sky in Doom II, you better save your level as MAP22, MAP23, ..., MAP30.

- Interior sectors: The easiest way to create a sector inside another sector using WinDEU is to insert 2 shapes, one on top of the other. The first time you insert a shape in the middle of an existing sector (say a 64x64 square), the lines should point "out," i.e. towards the existing sector (and will be labeled as referencing that sector. Now, if you create a second sector outside of the existing sector (in the nullspace of the level, so to speak), then drag it over to the square so that the vertices line up, the program will merge the vertices and lines so that you end up with 2-sided lines -- the first side still references the original sector, while the second side references the new one. At that point, make sure that:
- The floor of the new sector is low enough for the player to step up on it (<= 24 unit difference);
- The ceiling is high enough so that the player will fit (>= 56 units);
- The lines of the square are NOT "impassable" (they should automatically be tagged as 2-sided).
That should do it. I use WinDEU, as well, and I know that it has some pretty useful help stuff (and maybe even a simple tutorial) -- check out the Help menu and go from there.

or try read some of these tutorial, they help alot... :)

http://www.doomworld.com/tutorials/index.shtml

Thanks a lot guys! You've been a GREAT help! Now I can FINALLY start making levels.