Ashlee Simpson on Dancing with the Stars

Don't worry this is not a post about Ashlee Simpson, her engagement and supposed pregnancy. This is also not a post about Dancing with the Stars, which I have never watched till this season and now really enjoy. This is about the dress Ashlee wore when performing on the show last night. I LOVE IT! I want it so bad, it is so cute, and sexy and fun!

One problem I can not find out who it is by or any information on the dress. Please help! If anyone know or knows where I should look please let me know!