Julia, please be careful: DO NOT send any bitcoin to that address, ever!

You've published the private key, which means that anyone reading this can take the money by adding it to their own account! It's like the key to a house. If someone copies it, they can unlock the door just like the owner.

The only thing that keeps you in control of your cryptocurrency is that your private key MUST be kept private.

In your blockchain.info wallet, next to the Send button. simply click "Request" and it will give you a secure address. Just copy that address in order to send it from bitstamp.

Also, Bitstamp should also be able to give you your own "deposit" address so that you can send coins from your blockchain wallet to your bitstamp account, just using that Send button.