Array question

[TheLostGuru]

I have a dynamic array. This is my code thus far.

add_student = function () {
	var gender = _root.gender_text.text;
	var Name = _root.name_text.text;
	if(gender == "Male") {
		var length = _root.boys.length;
		_root.boys[length] = (Name);
                //Is this not possible?
		_root.boys[length][0] = "test";
		_root.boys[length][1] = "test2";
                //traces undefined
		trace(_root.boys[length][1]);
		
	}

}

I am trying to hurry and do this for a school project, but can't get the nested arrays to work. Anybody know what I am doing wrong?