After uploading my web application to my hosting company, i'm receiving an UnsupportedClassVersionError. I'm figuring this is because i've compiled my classes using JDK 1.5.0_06 whilst the JVM running in my host's server is the older 1.4.2_08. Obviously, if this was on my own machine i would just update the JVM. I'm not sure how keen my host will be though to do the same. Therefore, i was wondering if there are any other approaches to solve this problem. Obviously i could change my JDK to 1.4.2 and recompile but this somehow seems to be unsatisfactory...although i will do it if its the only solution. After reading a similar post from a couple of years back, someone replied with using switches. What are these and how do you use them? Any other comments would be greatly appreciated.