I have an Issue with the IsDBNull method.
This is my code:

```
   Dim a as Bool=  IIf(IsDBNull(reader("field")), _
                       False, _
                       Convert.ToBoolean(reader("field")))

```

The code above should return *False* if the column is false but I get the exception:

> 
> Impossible to cast DBNull to other types.
> 
> 
> 

The Convert.ToBoolean fails