you can use this function...
Protected Function Nz(ByVal vValue As Object, ByVal vDefValue As Object) As Object
If IsDBNull(vValue) Then
Return vDefValue
Else
If vValue Is Nothing Then
Return vDefValue
Else
Return vValue
End If
End If
End Function
'and call it this way
CType(Nz(drSqlReader.Item("SomeStringField"), ""), String)
'or
CType(Nz(drSqlReader.Item("SomeNumericField"), ""), Integer)