How To delete the white outline of an image in photoshop ??

[jossball]

i was deleting with the magic eraser in photoshop cs5, when i delete the white background of a car when i load it in a black background there is a white outline,
please i need help thanks, if posible answer me to sauleo_esteban@hotmail.com

[iDad]

what do you need?
there are plenty of ways to clean up the edges, if you could post the image Im sure one of use will have an idea for you