I have this trigger I want to make it allow multiple row updates, currently it handling only single row update.when i update record, it says sub query returning more then 1 value..

```
   GO
    ALTER TRIGGER [dbo].[OnReceiptUpdate]
    ON  [dbo].[paymentReceipt]
    AFTER UPDATE 
    AS 
    BEGIN   
    SET NOCOUNT ON;
    Declare   @correctdate VARCHAR(19);
   Declare   @receiptNo VARCHAR(50);
DECLARE @customerID NCHAR(50)
SET @customerID= (SELECT customerID FROM inserted)
 set @correctdate =  (SELECT CONVERT(VARCHAR(19),paymentDate,103) FROM inserted)   
  set @receiptNo =  (SELECT receiptNo FROM inserted)      
   BEGIN

   UPDATE Paymentreceipt
       SET paymentDate = @correctdate 
    WHERE customerID = @customerID and receiptNo=@receiptNo  
   END
 END

```