By DARLENE SUPERVILLE
WASHINGTON (AP) - Michelle Obama is celebrating her 50th birthday Friday.
The first lady is spending the day out of sight, with no public appearances after back-to-back events this week.
A birthday bash is on tap for Saturday night at the White House. President Barack Obama has been involved in the planning.
Officials are keeping a tight lid on party details, but guests have been told to come prepared to dance.
Mrs. Obama said last month she wasn't certain how she would spend her birthday but that whatever she did might involve some dancing.