You can comment a line by putting an asterisk (*) or the keyword NOTE at the beginning of the line. Commented line will change to green colour. The asterisk is used when you want to comment the whole line, from beginning till the end. If you want to put comment at the end of the line to describe what your code is doing, you can do so with double ampersand (&&)
Please note that if you end the comment line with a semi-colon, the next line will also be commented even though it is not started with asterisk.