How can I tell if my cats spraying?

Ok, first, if this is in the wrong place, then jsut move it. Anway, I looked on google, eyt nothing good came up. Charlie has peed in the sink twice and the hallw ay smells rather bad, eyt we don't see any dog 'you know what' there. Though our dogs, sally and tara, have been peeing int he house *now it's only when we're not home to let them out* I was jsut wounding if anyone has any advice or how to tell if he has been spraying. and he..well...went potty on my dads tie's.

KCT

a black light bulb bought from a hardware store should work.. turn off all the lights and then turn on the black light and shine it along the walls, any trace of urine should show up.

If I think my boys have pee'd somewhere on the wall, then I simply bleach all of the walls in that room. Until we get our Zero odor, that is.