I'm trying to create this proc:

--DROP PROC sp_GetCustomers

GO

CREATE PROCEDURE sp_GetCustomers
	@RecordId		INT = NULL,
	@FirstName		VARCHAR(30) = NULL,
	@LastName		VARCHAR(30) =NULL,
	@CreditLimit	MONEY = NULL,
	@State			VARCHAR(2) = NULL,
	@Active			BIT = NULL
	 
AS

	SELECT * 
		FROM Students
		WHERE ((@RecordId IS NULL) OR (RecordId = @RecordId)) AND 
			  ((@FirstName IS NULL) OR (FirstName = @FirstName)) AND 
			  ((@LastName IS NULL) OR (LastName = @LastName)) AND 
			  ((@CreditLimit IS NULL) OR (CreditLimit = @CreditLimit)) AND 
			  ((@State IS NULL) OR (State = @State)) AND 
			  ((@Active IS NULL) OR (Active = @Active)) 

I'm getting

Msg 207, Level 16, State 1, Procedure sp_GetCustomers, Line 17
Invalid column name 'CreditLimit'.
Msg 207, Level 16, State 1, Procedure sp_GetCustomers, Line 18
Invalid column name 'State'.
Msg 207, Level 16, State 1, Procedure sp_GetCustomers, Line 19
Invalid column name 'Active'.

The column names are correct.

Anyone?