SQL Substring How to combine first letter of every word in a column

 Hi,

    I wanted to know How can I combine the first letter of every word seperated by space in a column. I have got the query almost to work, For the second word it finds the result fine but for the third word it seems to go back to the first words first letter for ex:

SELECT     BANK_NAME, SUBSTRING(BANK_NAME, 1, 1) + SUBSTRING(BANK_NAME, CHARINDEX(' ', BANK_NAME) + 1, 1) + SUBSTRING(BANK_NAME,
                      CHARINDEX('  ', BANK_NAME) + 1, 1) AS Expr1
FROM         TBL_BANKS

Returns bob for

ABN Amro Bank         It should display AAB but it displays AAA
Alpha Credit Bank      It should display ACB but it displays ACA


I appreciate any one's help regarding the problem in advance.