i have below tables

tbl_rcv_items

st_id | item_id  |stock_opening_qnty |stock_received_qnty |stock_rcvd_date      
14       1          0                  70             2010-05-18        
15      16          0                 100             2010-05-06        
16      10          0                 59              2010-05-20        
17      14          0                 34              2010-05-20        
20      1            70                 5              2010-05-12 

tbl_issu_items

issue_id    refer_issue_id  item_id     item_qntt   item_updated
        51          1           1               5   2010-05-18 19:34:29
        52          1           16              6   2010-05-18 19:34:29
        53          1           10              7   2010-05-18 19:34:29
        54          1           14              8   2010-05-18 19:34:29
        75          7           1               12  2010-05-18 19:40:52
        76          7           16              1   2010-05-18 19:40:52
        77          7           10              1   2010-05-18 19:40:52
        78          7           14              1   2010-05-18 19:40:52
        79          8           1               3   2010-05-19 11:28:50
        80          8           16              5   2010-05-19 11:28:50
        81          8           10              6   2010-05-19 11:28:50
        82          8           14              7   2010-05-19 11:28:51  
        87          10          1               2   2010-05-19 12:51:03
        88          10          16              0   2010-05-19 12:51:03
        89          10          10              0   2010-05-19 12:51:03
        90          10          14              0   2010-05-19 12:51:03
        91          14          1               1   2010-05-19 18:43:58
        92          14          14              3   2010-05-19 18:43:58

tbl_item_detail

    item_id  item_name
     1         shirt
     2         belt
     10        ball pen
     14        vim powder
     16        pant

NOW if i want total available quantity for each item till today using both table

total available quantity for an item =stock_opening_qnty+stock_received_qnty(LATEST ENTRY FROM (tbl_rcv_item) for that item id according to stock_rcvd_date) - SUM(item_qntt)

for eg:

 if i want to know the available quantity for item_id=1 till today(25-05-2010) then it shoud be 70+5(latest entry for item_id till 25/5/2010)-23( issued till 25/5/2010)=52

i write below query ,

SELECT tri.item_id, tid.item_name, (tri.stock_opening_qnty + tri.stock_received_qnty) AS 
totalRcvQntt, SUM( tii.item_qntt ) AS totalIsudQntt  FROM tbl_rcv_items tri 
JOIN tbl_issu_items   tii ON tii.item_id = tri.item_id 
JOIN tbl_item_detail tid ON tid.item_id=tri.item_id WHERE 
tri.stock_rcvd_date <= CURDATE() GROUP BY (tri.item_id)

which results

Array
(
    [0] => Array
        (
            [item_id] => 1
            [item_name] => shirt
            [totalRcvQntt] => 70
            [totalIsudQntt] => 46
        )

    [1] => Array
        (
            [item_id] => 10
            [item_name] => ball pen
            [totalRcvQntt] => 59
            [totalIsudQntt] => 16
        )

    [2] => Array
        (
            [item_id] => 14
            [item_name] => vim powder
            [totalRcvQntt] => 34
            [totalIsudQntt] => 20
        )

    [3] => Array
        (
            [item_id] => 16
            [item_name] => pant
            [totalRcvQntt] => 100
            [totalIsudQntt] => 17
        )

)

in above result total isuse quantity for shirt(item_id=1) shoube be 23 whereas results reflects 46 bcoz there are two row regrading item_id=1 in tbl_rcv_items, i only need the latest one(means which stock_rcvd_date is less than tommorow)
please tell me where i doing mistake?? or rewrite the best query.

thanks a lot!