I have the following StoredProcedure.

CREATE PROCEDURE spPOItemAllocationCreate
@pPOItemID INT,
@pShipTo VARCHAR(100),
@pQuantity INT,
@pNotes VARCHAR(2000),
@pUser CHAR(10)
AS
DECLARE @ShipToID INT
SET @ShipToID = (SELECT ShipToID FROM dbo.ShipTo
     WHERE ShipTo=@pShipTo)
INSERT dbo.POItemAllocation(POItemID, ShipToID, Quantity, Notes, LastModifiedDate, LastModifiedUser)
VALUES (@pPOItemID,
     @ShipToID,
     @pQuantity,
     @pNotes,
     GETDATE(),
     @pUser)

I am passing values from code like

spPOItemAllocationCreate @pPOItemID=76,@pShipTo='Stores',@pQuantity=4,000,@ pNotes='Notes',@pUser='MM'


In table
POItemID int , ShipToID int , Quantity int, Notes varchar, LastModifiedDate datetime, LastModifiedUser char(10)

I am getting the following ERROR : : Must pass parameter number 4 and subsequent parameters as '@name = value'. After the form '@name = value' has been used, all subsequent parameters must be passed in the form '@name = value'

Call the procdure like this:
spPOItemAllocationCreate 76,'Stores',4000,'Notes','MM'

Yes. What jbenson001 said.

Your original query would've worked too, except you indicated the number 4000 as 4,000 (for @pQuantity) - a comma is strictly used to separate parameters, you can't use it in a number.