when green flag clicked
show
go to x: (position you want) y: (position you want)
forever
if <touching mouse pointer> then 
change [brightness] effect by (30)
else
set [brightness] effect to (0)
when this sprite clicked
if <[list] contains [username]> then 
say [Sorry! You can't vote more than once.] for (4) secs
else
change [yes] by (1)
add [username] to [already_voted_list]
end

To make the no script, you do the same thing but add the point to the no variable instead.