(Pullman, WA)  --  Researchers at Washington State University say they're developing a breathalyzer that detects marijuana use.  They say they hope to have the device ready for field use sometime next year.  WSU chemistry professor Herbert Hill says the breathalyzer is designed to work like the portable breath monitors that are currently used to test for alcohol consumption.  Hill says the first round of testing has been completed, and a second round of testing is about to start.