My husband installed our dishwasher a Westinghouse 905 and it fills with water but then floods our kitchen!! If we turn it off it drains out properly so we are not sure what to do next. Any help would be appreciated greatly!!!

Check the outlet hose goes UP at least 50-60cm before going down to the drain point, if not all water will syphon out as soon as it goes in

Hello!
"floods the kitchen"... do you mean it overfills, or that it fills, the water valve shuts off, and then while running it leaks out?
Perhaps the water level control float that is on the inside of the machine is stuck or there is packing material inside it for shipping???
The float valve would be on the bottom of the tub and probably looks about the size of a hockey puck and has to move freely up and down to detect the level of water. If the water level were to get too high, the valve will float up and release a micro switch that it controls with a little shaft that runs down through a small opening in the bottom of the tub.
Check to see that it moves freely up and down... you likely will be able to hear a bit of a "click" of a micro switch.
If the float was stuck, it probably is safe to try to run the dishwasher again... but stand by just in case !!!!
Hope this was the problem and now it works !!!
/denis