Writing the sql code for dropdown in Reporting services

This is my criteria below for my parameters and sql code given pleas asisst

Criteria will be

• Product type : All or product types (Drop down)
• ISBN field : if empty then ignore
• Date Start, Date End  = default to today

use BusinessEvents

use BusinessEvents

SELECT  oh.[OrderId]

     ,oh.[CustomerId]

    , c.FirstName +' '+ c.LastNameas CustomerName

       ,oh.[OrderDate]

        ,P.ProdId

       ,P.Barcode

       , rtrim(p.ProdName+' '+isnull(p.subtitle,''))

     , op.[Type] as PaymentMethod

     , oce.Quantity as ItemQty

     , oce.Price as ItemPrice

     , oh.Statusas OrderStatus

     ,oce.Statusas ItemStatus

  FROM [dbo].[OrderHeader] oh(NOLOCK)

  leftouterjoin dbo.Customer c(NOLOCK)on oh.CustomerId = c.CustomerId

  leftouterjoin [dbo].[OrderPayment] op(NOLOCK)on oh.OrderId = op.orderId

  leftouterjoin [dbo].[OrderConsignment] oc(NOLOCK)on oh.OrderId = oc.orderId

  leftouterjoin [dbo].[OrderConsignmentEntry] oce(NOLOCK)on oc.ConsignmentCode= oce.ConsignmentCode

  innerjoin product..Product p(nolock)on oce.ProductId = p.prodId

  innerjoin product..producttype pt(NOLOCK)on p.prodTypeId = pt.prodTypeId

  Where

     (pt.ProductType={report field : Product Type}or  {report field}='All')

  and

      p.Barcodelike'%'+{Report field : Barcode}

  and

      oh.[OrderDate]>={report field:Date start}

  and

      oh.[OrderDate]<={report field:Date End}

  orderby oh.orderid