I didn't mean to vote on [this answer][1] but have accidently clicked 'vote up'. Then I clicked 'vote down' to undo previous vote. I think it doesn't do what I expected, it just adds 10 and then subtracts 2 from reputation of one who gave the answer, and subtracts 1 from voter's reputation. Is there any way to undo such actions ? [1]: http://stackoverflow.com/questions/1063497/hidden-features-of-erlang/1086640#1086640