I wasn't bagging on you for it being simple, thats fine, you don't have to defend yourself. And i don't know about visual basic, but in normal, real life, X+ is going to the right. Think about algebra 1, remember plotting graphs and stuff? Heres some links

http://srmwww.gov.bc.ca/risc/pubs/teecolo/...ssets/hmgf6.gif
http://members.jcom.home.ne.jp/maegawa/pub...s-d/xy2ps-3.png
http://www.pen.k12.va.us/Div/Winchester/jh...ebra/grapha.jpg

If you still dont believe me, just go to google and search "X and Y axis".