Query to calculate total based on field criteria

Hi,

I'm using SQL Server 2005 to create a query to use in an Access 2003 report.

The SQL statement is as follows:
SELECT     dbo.tbl_entities.fld_entityname, dbo.tbl_codes.fld_year, dbo.tbl_categories.fld_categoryname, dbo.tbl_subcategories.fld_subcategoryname,
                      dbo.tbl_budget.fld_purpose, dbo.tbl_budget.fld_unitcost * dbo.tbl_budget.fld_quantity AS fld_total
FROM         dbo.tbl_budget INNER JOIN
                      dbo.tbl_categories ON dbo.tbl_budget.fld_categorycode = dbo.tbl_categories.fld_categorycode INNER JOIN
                      dbo.tbl_subcategories ON dbo.tbl_budget.fld_subcategorycode = dbo.tbl_subcategories.fld_subcategorycode INNER JOIN
                      dbo.tbl_codes ON dbo.tbl_budget.fld_code = dbo.tbl_codes.fld_code INNER JOIN
                      dbo.tbl_entities ON dbo.tbl_codes.fld_entitycode = dbo.tbl_entities.fld_entitycode

The result i get is as follows:
Entity    Year              Category               Subcategory    Purpose      Total

IGB        20072008      Hardware              Others              Exp               9000.0
IGB        20072008      Office Equipment   Others              Exp             1000.0
IGB        20072008      Hardware              Laptop              Ren             2000.0
IGB        20072008      Hardware              Desktop            Ren             4000.0
IGB        20072008      Hardware              Laptop              Prj                 4000.0
IGB        20072008      Hardware              Laptop              Prj                 4000.0

I need to modify the SQL statement, so that instead of one field as "purpose" and another field as "total", i have three fields as "total_exp", "total_ren" and "total_prj" So basically, i want a total field that's based on a criteria of another field in the same table. So my final query will look like this:

Entity    Year              Category               Subcategory    Total_Exp     Total_Ren     Total_Prj

IGB        20072008      Hardware              Others              9000.0          0                   0
IGB        20072008      Office Equipment   Others              1000.0          0                   0
IGB        20072008      Hardware              Laptop              0                  2000.0           0
IGB        20072008      Hardware              Desktop            0                  4000.0           0
IGB        20072008      Hardware              Laptop              Prj                 8000.0Start Free Trial