OK, so I finally got my Wifi to stop quitting on me before it connects to Nintendo WFC, but when it starts searching for a gift, the system gives me the error code 31020: 'Download Failed.' WTH. Somebody help me.
You go to mystery gift
Here are the steps
Go to the menu where your save is shown. (Don't click your save)
Scroll down until you see the words "Mystery Gift"
Click Mystery Gift
It will have four options, "Gift Album", "Info","Quit", or "Recieve Gift"(Click Recieve Gift)
It will say " The communication channel must be open to recieve Mystery Gifts. Is that OK?" (Press yes)
You will have four options, "Get Via Wireless", "Get Via Nintendo Wi-Fi", "Get Via Infraded", and "Back". (Select Nintendo Wi-Fi)
It will ask you to connect, and you press yes.
once connected click recieve gift, and after a moment deoxys will appear
Go to your save and go to a Pokemon Center
Make shure you have one open slot in your party for deoxys.
Finally Talk to the man in blue and recieve deoxys from him.
If this dosn't work it is a bug or glitch. But errors can be delt with when trouble shooting.
You should follow what Denno Senshi Porygon said,but if you are not in the USAor don't have your DS clock set to it's time,you will not get your Deoxys.