multidimensional array sorting

I have a text file which I read into an 2-D array so each row holds the date in its pieces and the event title. I want to sort this array based on the day of the month in ascending order. The array is setup like this: January,7,2003,event title January,1,2003,event title January,4,2003,event title $list[0][0] = "January"; $list[0][1] = 3; $list[0][2] = 2003; $list[0][3] = "event title"; This is the way I was trying to sort the array but the order doesn't seem to change. usort($lines,compare); function compare($x,$y) { If ($x[1] == $y[1]) return 0; else If ($x[1] < $y[1]) return -1; else return 1; } Kelly