Please at the moment poll don't give anykind of message for voter and also allow define color for voted line. I would like to have RED line for voted line because all the lines are black and it took me while to figure that my wote is bold black. Better would be definable color.
well, you can change the poll line color in index.css - like any other theme color change....
Why waste a user's time with a separate thankyou message?