Britney Spears stepped out in a striped top and heels to get to work in LA this afternoon. She's been a regular at the dance studio all week after releasing her first single, "Hold It Against Me," with amazing success on Tuesday. The song is No. 1 on iTunes in multiple countries and is even getting praise from fellow pop star Miley Cyrus. Britney's now prepping for the music video, which her manager, Adam Leber, seems to think is going to be just as impressive.