IsNull (function)

Syntax IsNull (expression)
Description Returns True if expression is a Variant variable that contains no valid data; returns False otherwise.
Comments The IsNull function is the same as the following: 
  (VarType(expression) = ebNull)
Example 
Sub Main()
  Dim a As Variant     'Initialized as Empty
  If IsNull(a) Then MsgBox "The variable contains no valid data."
  a = Empty * Null
  If IsNull(a) Then MsgBox "Null propagated through the expression."
End Sub
See Also Empty (constant); Variant (data type); IsEmpty (function); IsDate (function); IsError (function); IsObject (function); VarType (function).