Changing build settings bug

I was creating a car game for android but I built it, luckily only some of it, on the desktop standalone build. When I found out I had to create the project on the android build settings to use android remote I changed the settings. Of course, something went wrong. All of my code that worked became riddled with errors. It seemed to be only variables that had not been defined. They had been defined in another script and I was calling the var data from them to keep the code neater. Also, vars defined in for loops didn't work e.g. for(i=0 ...) i was apparantly not defined. When I changed the build settings back to pc all the code started to work again properly. I am using javascript... Thanks for any help.