You only get those case to work for iVal values of 1 to 10. Then the first thing you do when the are called is check incorrectly if they are in another range altogether. Therefore nothing can ever be executed.
AHA! Grumpy_Mike turned on the light for me and it's my bad. I failed to explain that I will be using the pot as a multi-position "switch". The pot will be set thusly... case 1: pot will be set to analog 100... case 2: pot will be set to analog 200... etc. etc. (And therein lies my answer) The pot will never be set to 150 or any other value other than the midpoint of each range. (e.g. 100, 200, 300, 400, 500 etc.) I apologize for not explaining this earlier. The function won't even be called until a pushbutton is pressed. That button is scanned by the other switch/case I mentioned earlier, and is working flawlessly.
Looking back at the code, I see my problem. I would have to first declare another var, (e.g. range) and set that to an integer between 1 and 10 using analogRead(). Then the switch/case var would become range, not iVal. To determine the value of "range", I would have to use the "if" statements first. Therefore switch/case becomes redundant. DUH! Oh well, like I said, I'm really a newbie at software. I'm a hardware tech.
Thanks, everyone, for the input. It did make me see what I was doing wrong. Hope this may help someone in the future. I learned something new from all of this.