opening & closing stock

i am using sql server 2008

my table is 

CREATE TABLE [dbo].[tbl_enventry](
[TransactionDate] [smalldatetime] NULL,
[Item] [char](1) NULL,
[RecQty] [int] NULL,
[IssueQty] [int] NULL

(

i have written query as

DECLARE @StartDate SMALLDATETIME = '2011-06-01 00:00:00', 
        @EndDate      SMALLDATETIME = '2011-06-02 00:00:00';

WITH opneningBalance(Item, prevR, prevI) AS
(
    SELECT 
        Item,
        SUM(RecQty),
        SUM(IssueQty)

    FROM tbl_enventry 
    WHERE TransactionDate < @EndDate
    GROUP BY Item
),

 CurrentBalance(Item, curR, curI) AS
(
    SELECT 
        Item,
        SUM(RecQty),
        SUM(IssueQty)
    FROM tbl_enventry 
    WHERE TransactionDate BETWEEN @StartDate AND @EndDate
    GROUP BY Item
)
SELECT 
    CurrentBalance.Item,
    Opening = ISNULL(prevR,0) - ISNULL(prevI,0),
    RecQty = curR,
    IssueQty = curI,
    BalanceQty = ISNULL(prevR,0) - ISNULL(prevI,0) + (curR - curI)
    FROM         CurrentBalance inner JOIN

                      opneningBalance 
ON CurrentBalance.Item = opneningBalance.Item  ;

if opening balance is null then all data showing balank, if i used full outter joint or right out joint it give wrong data, please help me i want result as

Item  Opening                                 RecQty      IssueQty    BalanceQty
---- --------------------------------------- ----------- ----------- ---------------------------------------
A       10                                           10            0                20

---

Thanks Best Regard Naweez