its because of the array size you define as [3,7,1] so you need to specify 1 slot for the z-axis.
And if you do ["Africa",1,2,3,4,5,6] the enclosed [] will be 1 slot. So you cant get anything back as the format is wrong. Doing [["Africa"],[1],[2],[3],[4],[5],[6]] will set each of the item inside [] as a slot.
So basically:
[
["Africa"],[1],[2],[3],[4],[5],[6]] is "size":[1,7,0]
[[
["Africa"],[1],[2],[3],[4],[5],[6]]] is "size":[1,7,1]
eg1: [x0[y0][y1],[y2],[y3],[y4],[y5],[y6]]
eg2: [x0[y0][y1],[y2],[y3],[y4],[y5],[y6]],
[x1[y0][y1],[y2],[y3],[y4],[y5],[y6]]
Something like that. I hope i'm not wrong. <img src="smileys/smiley24.gif" border="0" align="middle" />