Date object question. (9 is Oct )

1

i wanted to create a date object for 2008/SEPTEMBER/19.
so I wrote the following.


var myTime:Date = new Date(2008,09,19,12,0,0);
trace(myTime);  // Sun Oct 19 12:00:00 GMT+0300 2008

as you can see, i prints Oct instead of Sep.
why is this happening?
what`s the logic behind date object?