Sorry, I couldn't find pricing data for that day. The closing price for Microsoft (MSFT) on May 13, 2011 was $19.19. It was down 1% for the day. The latest price is $479.28.
DATE
OPEN
HIGH
LOW
CLOSE
VOLUME
May 13 2011
$19.38
$19.41
$19.13
$19.19
66,819,289
Daily pricing data for Microsoft dates back to 3/13/1986, and may be incomplete.