I have included in my VBA a line that reads:
MsgBox "Available from 1 to 150 MHz"
whenever there is an frequency entry (column M) in that is lower than 1 or higher than 150.
However, the message box just keeps on popping up, even when the frequency section is empty. You will see what I mean when you click on the drop down list in the attached file.
I even added a case: Not IsEmpty (Cell M). Please tell me how I can fix this bug.