SQL If Statement Not Working Correctly

My if statement never seems to do anything. I am inputting @active from an ASP page, and @cactive is set through the selecting of CActive from the Cots Table. Do you guys see anything wrong with this statement? Why doesn't it ever exec开发者_JAVA技巧ute? Im using SQL Server 2005

//Declare Variables Here (about 20)

AS
If @currentdate is null
SET @currentdate = GETDATE()

Update Cots
SET //UPDATE ALL FIELDS HERE
Where CoID = @CID

SET @cactive =
(
Select CActive
From Cots
Where CoID = @CID
)

If @cactive != @active
Begin
INSERT INTO Activity
        (CoID,ActivityDate, ActivityName, ActivityNote, ActivityMediaContact, ActivityOwner)
        Values (@CID, @currentdate, 'Co ' + @fname + ' ' + @lname + 'made inactive','Co made inactive on ' + CAST(@currentdate AS varchar(50)), 'User', 'User')
End

INSERT INTO Activity
        (CoID,ActivityDate, ActivityName, ActivityNote, ActivityMediaContact, ActivityOwner)
        Values (@CID, @currentdate, 'Updated ' + @fname + ' ' + @lname,'Updated on ' + CAST(@currentdate AS varchar(50)), 'User', 'User')

---

If either of these is null, they will never be equal or not equal

If @cactive != @active

Example

DECLARE @i int, @i2 int
IF @i <> @i2
PRINT 'not equal'

IF @i = @i2
PRINT 'equal'

Check for NULLS also by using ISNULL()/COALESCE() or IS NULL/IS NOT NULL

---

Using IS NULL is best for checking a condition, like in a WHERE clause.

You should use the ISNULL() function...

USE AdventureWorks2008R2;
GO
SELECT AVG(ISNULL(Weight, 50))
FROM Production.Product;
GO