Fix isInRange for strings

band-plan.html

@@ -117,7 +117,7 @@ div>label {
 		}
 
 		function isInRange(number, min, max) {
-			return number >= min && number <= max;
+			return Number(number) >= Number(min) && Number(number) <= Number(max);
 		}
 
 		function add_power(ext, row) {