How to use Bitcoin Wallet with MtGox?
You need to buy bitcoins on MtGox using another currency. These bitcoins will show up on your MtGox account.

You can then withdraw these bitcoins from your MtGox account to your own wallet. You can find this under Funding options &gt; Withdraw funds &gt; Bitcoin. Enter the address your wallet gives you and MtGox will send your coins to that address so that they show up in your wallet.