请教：多维数组生成排序问题

Array
(
    [0] => Array
        (
            [vsort_id] => 1
            [veg_id] => 748
            [veg_name] => 原汁慢煮焖煨中东干鲍鱼
            [veg_preprice] => 788
            [veg_favprice] => 788
            [veg_picstr] => jdcpic1342688600.jpg
            [veg_ptfs] => 
            [veg_ts] => 0
            [veg_fj] => 
        )    [1] => Array
        (
            [vsort_id] => 1
            [veg_id] => 749
            [veg_name] => 秘制日本二十头极品鲍鱼
            [veg_preprice] => 888
            [veg_favprice] => 888
            [veg_picstr] => jdcpic1342688648.jpg
            [veg_ptfs] => 
            [veg_ts] => 0
            [veg_fj] => 
        )    [2] => Array
        (
            [vsort_id] => 3
            [veg_id] => 750
            [veg_name] => 时日老火例汤
            [veg_preprice] => 86
            [veg_favprice] => 86
            [veg_picstr] => jdcpic1342688717.jpg
            [veg_ptfs] => 
            [veg_ts] => 0
            [veg_fj] => 
        ))有以下一自动生成的数组，请教一下大家有没有将vsort_id这一列挑出来，然后根据其值对数组进行排序的方法，排序后的数组如下形式：$a=array(
    "2" => Array
        (
            "1" => Array
                (
                    "id" => 728,
                    "name" => "玉带香油莴笋",
                    "preprice" => 68,
                    "favprice" => 68,
                    "pic" => jdcpic1342685874.jpg,
                    "num" => 1,
                    "ts" => 0,
                    "fj" => ""
                ),
            "2" => Array
                (
                    "id" => 727,
                    "name" => 新杭帮熏鱼,
                    "preprice" => 38,
                    "favprice" => 38,
                    "pic" => jdcpic1342685755.jpg,
                    "num" => 1,
                    "ts" => 0,
                    "fj" => ""
                )        ),
    "1" => Array
        (
            "1" => Array
                (
                    "id" => 749,
                    "name" => 秘制日本二十头极品鲍鱼,
                    "preprice" => 888,
                    "favprice" => 888,
                    "pic" => jdcpic1342688648.jpg,
                    "num" => 5,
                    "ts" => 0,
                    "fj" => ""
                ),
            "2" => Array
                (
                    "id" => 748,
                    "name" => 原汁慢煮焖煨中东干鲍鱼,
                    "preprice" => 788,
                    "favprice" => 788,
                    "pic" => jdcpic1342688600.jpg,
                    "num" => 1,
                    "ts" => 0,
                    "fj" => ""
                ),
            "3" => Array
                (
                    "id" => 747,
                    "name" => 炝椒酱爆嫩鸡丁,
                    "preprice" => 20,
                    "favprice" => 20,
                    "pic" => jdcpic1342688515.jpg,
                    "num" => 1,
                    "ts" => 0,
                    "fj" => ""
                )
        )
);
谢谢大家帮忙解答