Trouble with Is Null in Expression 1

[dianemarie]

Hello, SQL Server 2005. I am trying to conditionally hide a table row. In the Visibility properties I am trying to say "if doctype = 6 or if there is no doctype for the row (no record) then hide the row, else show it". I have tried several ways to indicate "is null" to no avail. The expression below doesn't work either. Can anyone tell me where I'm going wrong here? It keeps telling me I have an error in the expression. Thanks much.

=iif(Fields!doctype.Value = 6, true,
iif (Fields!doctype.value = "", true,
false)

 

[RiverGuy]

Use Is Nothing. Here is an example

=iif(Fields!SomeField.Value Is Nothing = true, "NULL!!!", "not null")

 

[dianemarie]

I got this to work using the "is nothing". Thanks a lot, I appreciate it!