point and shoot cameras do have sensors but internal ones, that means you cant access them like D-SLRs. I guess you took your camera to the beach for some shootout, am I right ? that's usually where all hell breaks lose. water particles splash on your lenses and dries upon the special coating present on them.
I strongly suggest you not to attempt cleaning it yourself since you may get a permanent scratch on it then. take it to a service center or the mall where you bought it from. they can do it for you at a nominal cost. let me know if you need more help.