Modded a couple of things in the script

Added "WARN" to responses
Swapped out the ticks and crosses from the reponses as they dont work on all systems. Replaced with "OK", "ERROR"
Replaced common programs in the script with variables containing full paths to programs
Moved dmesg output in to a var. Was no point in keep running the program esp if system is under heavy load.
altered service checks to be triggered from a for loop. Moved services to check for in to single var to make this work easier.
altered swap check to warn if there is no swap on the system instead of returning nothing.