I changed a light switch, and now have no voltage. What happened?

My light worked. I replaced one of the three way switches that operated it using the wiring diagram provided. The new switch did not work when I turned the power back on. I tried the old switch again, it does not work. I removed both switches and tested only the exposed wires and found that I have essentially no voltage at that site all of the sudden. Every other light/receptical on that circuit works and has full voltage, except this one. What happened and how do I get voltage back to this light?I changed a light switch, and now have no voltage. What happened?try thisI changed a light switch, and now have no voltage. What happened?The box should have three wires into it plus a ground. You should have a black, white and red. On the three way switch you will see one screw painted black, this is for the black wire. Opposite the black screw you will see a brass colored screw, this is where the white wire is connected to and the red ties into the other brass screw. Is this doesn't work you will have to switch the white and red wires, called travellers. Does this box have other wires in it? This could be the feed side and then you will have to swap out the black wires, one will be alive. This one will go to the black screw and the black one removed will go to the light.I changed a light switch, and now have no voltage. What happened?if it wasn't broke,why did you fix it?