NOT

After briefly scanning all the posts I don't think anyone mentioned that the reason it didn't work for you is simply because you had NOT in the wrong place. In my experience NOT comes before the value check, otherwise Blitz would be thinking Not is the variable you are checking. So,,,

IF soundflag Not = 1

should read...

If NOT soundflag = 1

In english you are saying "if soundflag doesn't = 1"