How do I repair a porch light that isn't working? Details below.?

The porch light is suspended from the ceiling of the porch by a cable. It holds 4 bulbs. Even after I change the bulbs (which work on other lamps), the porch light won't go on when I throw the light switch. What can I do? Thanks.
How do I repair a porch light that isn't working? Details below.?
It is either the switch or the fixture itself..Take the fixture off and make sure the two wires are connected(actually 3 to include ground..Hot wire is black, nuetral is white..and the bare copper wire or green wire is ground...I seriously doubt it is a breaker at all for they would not make a dedicated circuit for one simple porch light..there would be more than likely 4 or 5 other plugs and/or lights attached to that circuit..unless you have other items not turning on..it is not the breaker/fuse...If they wired every outlet to a dedicated circuit..you have 40 or 50 breakers in a box..if you could find a service center to hold that many...
How do I repair a porch light that isn't working? Details below.?
It could be any one of several problems. If you have already changed the bulbs, I would then check the light switch. If after testing the switch and finding that it is sending current, then you have a loose connection or a broken wire somewhere between the switch and the fixture. Hope that this helps.
when all else fails check the fuse
The problem could lie in the light, the wire going from the light, or the switch, you could have a loose connection in your box above the light or in the switch box. Hopefully the wire runs from your switch to the light. If you have a cheap voltage tester, it would solve alot of problems. Check to see if you have power at your switch with the switch off. do thid by putting one of the probes on the black (hot ) wire and the other to ground(bare or green wire ) or to the neutral(white wire) If you have power there, check the other wire on the switch the same way. This wire is your switch leg. If you have power there, your switch is fine. If not replace your switch. Next take the light down from the light box. Check for power there, with the switch on. If you have power there, check your wire connections. If they are all tight and good, you have a bad light, If not, get in the attic and follow the path of electricity in till you get power to your light.

Good luck