venting is good. proper ventilation while painting is important.
the paint needs adequate drying time... if you JUST did it, it will probably peel or bleed into the other color. be patient and let the paint dry thoroughly.
(bushwacker says tacky, he has painted more than I have, so go with his answer.)
there might be something on this link that could help you. http://www.diynetwork.com/diy/pt_interior/0,2036,DIY_14206,00.html