it won't be the top key as the buttons don't match to the nissan key, the buttons are in a single capsule that you transfer, buttons and all.
i hope that it looks good, the seller said it will fit the key but he was a little weird with the answer he gave. ho hum, it was only 14 quid.
Sparky
If its the same one that I picked up on ebay then you could have got it for £8 from him
I posted a guide somewhere on how to do it but I cant be arsed to find it