Making connect four

noobsftw

I'm trying to make a version of connect 4 on vb. So far i have a 7x6 control array w/ labels. all i've figured out is how to make the objects fall down to the first available slot. basically i need some help like how can i make it change the player's turns and changing the shape for the gameboard after each turn . oh and i need to make a variable tiegame so after the gameboard fills up with 42 pieces it declares it a tie. How would i set it so it counts +1 after every turn. i'll probably have to ask for more help as i progress so thanks for the help in advance lol