Using Stored Procedures OUTPUT paramaters with SSRS

Hello there
Iam quite new to SSRS and
Iam trying to create a simple report to demonstrate the use of the output paramater in a sp and how SSRS will receive this parameter. As an example lets assume we have a sp called USP_Passoutput_ww.
Use Adventureworks;
go
Create Procedure USP_Passoutput_ww
@Product varchar(40) ,
@MaxPrice money ,
@ComparePrice money OUTPUT,
@ListPrice money OUT
AS

SELECT p.[Name] AS Product, p.ListPrice AS 'List Price'
FROM Production.Product AS p
JOIN Production.ProductSubcategory AS s
ON p.ProductSubcategoryID = s.ProductSubcategoryID
WHERE s.[Name] LIKE @Product AND p.ListPrice < @MaxPrice


-- Populate the output variable @ListPprice.
SET @ListPrice = (SELECT MAX(p.ListPrice)
FROM Production.Product AS p
JOIN Production.ProductSubcategory AS s
ON p.ProductSubcategoryID = s.ProductSubcategoryID
WHERE s.[Name] LIKE @Product AND p.ListPrice < @MaxPrice);

-- Populate the output variable @compareprice.
SET @ComparePrice = @MaxPrice;
GO
This is how the above sp would be called in TSQL which iam fine with:
DECLARE @ComparePrice money,
@Listprice money

EXECUTE SP_Passoutput_ww
'%Bikes%',
700,
@ComparePrice OUT,
@Listprice OUTPUT
IF @Listprice <= @ComparePrice
BEGIN
PRINT 'These products can be purchased for less than
$'+RTRIM(CAST(@ComparePrice AS varchar(20)))+'.'
END
ELSE
PRINT 'The prices for all products in this category exceed
$'+ RTRIM(CAST(@ComparePrice AS varchar(20)))+'.'
Iam familiar with the way of working with paramaters in SSRS and i can build the report to let a user send the input parameters (%Bikes%',
700) to the procedure. When i specify the @ComparePrice OUT,
@Listprice OUTPUT paramaters in the dataset properties i get an error. But iam unsure as to how SSRS can receive the 2 output parameters back from the proc. Can anyone shed some light on this as 3 of the books and tutorials i have worked through does not mention Output params with Stored Procedures.