If you use Option Explicit, you can make variable declaration mandatory. I always use that anymore. I find that it helps me not have typos as bad.

Access doesn't require that you initialize your variables like some other programs do, but I tend to do that as well, just out of good practice. I want to know where my starting point is.


Option Explicit

Then I think it would be appropriate to turn off Option Explicit for a while until I start with Developer1. I'm currently working on Expert 10 so I still have a long way to go.

Actually Ludwig I would recommend just the opposite.  I find that it actually prevents errors.
If you don't declare a variable then Access automatically assigns it as a variant which I find can cause other issues.

When I declare Dim WhereStr As String , I still get the error message that it has not been declared.  It's a string after all....or not ???

Have you declared the variable in the correct place?

Scope