What I've tried to do here is to highlight to you what a null is (an unknown value, not equal to anything) and how it differs from an blank string.


This is why we do not get a true or false value when comparing things to null; we get another unknown result!


Luckily, we can ask this question: Is this value unknown? I.e. is this value a null?

So if you look back at my first post in this thread, I have used a lovely function called IsNull() that performs this check.


I know we've taken a pretty windy route, but I hope it has explained to you why your intial code wasn't working as you'd expected.

As always, come back with any questions you have