can i change button list in Real time? like when i pressed one button,another button showed up.Can i do that?!

Yes.

how?

edit: i was trying that,it was crushing.....

What buttons are you trying to work with? What is your code currently?

in actionPerformed:

super.actionPerformed(guibutton);
	switch(guibutton.id) {
	case 1:
		*doing somting*
                        buttonList.clear();
                        buttonList.add(new GuiButton(2, 7, 10, 20, 20, "+"));
		break;
	}

And what happens when you try to run this code?

ups....i want to kill eclipse with his bad tips......so yea,it actyally work's.......

heh then can you help me with last quastin:can i send info to client when it opening gui?! like is client owner of this block or no.Like IC2 does with Trade O mat.

I think that all you need to do is override isUsableByPlayer(EntityPlayer) in your TileEntity.

alredy did,and what,send packet there?

I don't think there should need to be any packets involved. Is it not denying players access?

i dont need to deny acces,i need to send boolean varible to client,to draw a litle bit diffrent gui.....really,a litle bit.Just one diffrent button,and i dont want to create new gui for that.

Aah, my mistake. I'd say you pass the player to the GUI class from your proxy, and then check, in your proxy, if that player matches the player associated with the TileEntity.