I check the web and they only show you how to sort the whole array. I would like to be able to sort the subset of the 2D array. Here's my array.

var myArray=new Array(
new Array("af","ad","az","ab"),
new Array("bc","bd","bg","bb","bx"),
new Array("cf","ck","ca","cv","co"),
new Array("dd"));
How would I sort the sub array independently. So only the a's together, then only the b's together, etc.