How can i cancel my air tickets?

I have booked air tickets for southwest airlines and airtrans airlines. They are non-refundable. For some minor reason I wont be able to use them. How can i cancel those. Pls. help.How can i cancel my air tickets?
Occasionally you'll find that you will be offered credits or the ability to rebook at a later date for an additional fee, but the only way to confirm this is to contact the airline directly, for Southwest, call 1-800-I-FLY-SWA (1-800-435-9792)
Well, if it is a low cost airline then maybe you won't get a penny back from them if they states that it is non-refundable. But if it's a good airline then you maybe eligible to get refund if you ask for it atleast 48 hours before your flight departure date/time. This 48 hours early departure cancellation allowance by airline is a international rule but doesn't applicable to the low cost airlines. I suggest, you check with their policy clearly regarding your ticket and it depends what type/class of ticket you purchased. And also, restricted fare ticket won't have any refund at all.How can i cancel my air tickets?
You can call the airlines and cancel the tickets. You will not get any money back as the tickets are non-refundable.