Lighting, Light Fixtures, Ceiling and Exhaust Fans - Old 3 way switch to new 3 way switch

I live in a very old house and I am replacing an old 3-way light switch with a new one. When I took the old switch out there were three wires down one side of the switch. The new switch has one place for a wire on one side of the switch and two places on the other side, one of the screws is black. There are 3 wires red, black and white, coming out from the box. Question is which wire goes to which screw? Can anyone tell me which wire goes where?

Thank You
Karen

The important thing is to move the wire which was on the "common" screw on the old switch to the "common" screw on the new switch. The common screw might be in an entirely different position on the two switches. Common screws are often colored black and/or marked "COM" embossed on the back of the switch in tiny letters.

If it is too late to heed this advice, it is acceptable to use trial and error. There are only three possibilities, so it won't take long.

Thank You John. Trial and error prevails.