Passing value from stor oroc to Trigger [Resolved]

Hi All,
I have created a sp like this

ALTER PROCEDURE [dbo].[SP_WaterPH]
-- Add the parameters for the stored procedure here
@iReqDetailsId int =null
,@iReqSampleId int=null
,@iReqId bigint=null
.
.
.

now i am creating a trigger
like this

alter TRIGGER trgAfterUpdate ON [dbo].[tbl_RequisitionMaster]
FOR UPDATE
AS
Declare @iReqId bigint=null;
Declare @iReqStatus bigint=null;
Set @iReqStatus = (select min(reqdetailsstatus) as status from tbl_RequisitionDetails where ReqId=@iReqId);


now my problem is that how can i pass this " @iReqId " to trigger ?

any help please...

Thanks

[Resolved]