Help me

I have a few questions.

How do I prevent the unit from attacking or being attack until he go to his corpse?

How do you make it leave the entire corpse after a unit dies?

How do I make a creep appear neutral (yellow) until attacked?

how do I get the number of players that are playing?

You can prevent units from being attacked by giving them the ability "invulnerable - neutral" or something like that. You can prevent them from attacking by disabling their attack in the object editor.

The corpse-dissapearing-into-the-ground-leaving-only-a-skeleton is part of the unit's animation. Just pause the unit's animation after it dies and it should work. There may be some fields under gameplay constants where you might be able to change this.

Place it for the neutral pasive player and make a trigger which, when a unit owned by neutral pasive is attacked, gives that unit to neutral hostile.

There's a condition called player slot status comparison. This tells you if a player is playing, has left the game or was never even there. Make a loop that goes from 1 to 12 and checks for each player if he is playing, using this condition. If the player is playing, then increase an integer variable by 1. At the end of the loop, the variable will show how many players were playing. (if you use that variable for anything else earlier, make sure you set it to 0 before the loop)

thanks,

but for the unit not attacking thing. I need to be able to do it in game.
Where i can change it from attacking to non-attacking. you know

set acquisition range to 0

If you are looking for a "ghost return on corpse" resurrection script i suggest you to download the Halloween blizzard map "Candy War".
Look on bnet site to download it, as all blizzard maps its unprotected and u can look how it works.
When you die the unit is paused and the Death animation is played by trigger, a shade is spawned in the base and when you reach the corspe with the shade the hero is resurrected.

ok thanks dude