NZ function in SQL

[Jason Gentry]

How would I rewrite this to be compatible with T-SQL?

SELECT Challenges.*, ChallengeStatus(nz([Type],0),nz([Initiated Date],0),nz([OrderedDate],0),nz([DeliveredDate],0),nz([AnsweredDate],0),nz([Completed Date],0),nz([CanceledDate],0)) AS Status FROM Challenges ORDER BY Challenges.ID;

[Rabbit]

Please use code tags when posting code.

The equivalent function in SQL Server is ISNULL.