major.minor version

Im getting unsupported major.minor version exception while doing web applications using both tomcat5.0 and weblogic8.1, on the JVMs 1.4 and 1.5.Where did i do mistake?
[181 byte] By [ravi1567a] at [2007-11-26 16:39:05]
# 1
You are using different versions of jre and jdk, please change one of them and the problem would go.CheersVarun Rathore
Varun_Rathorea at 2007-7-8 23:05:56 > top of Java-index,Enterprise & Remote Computing,Web Tier APIs...
# 2
You can't run 1.5 class files on a 1.4 JVM unless you compile them with -target 1.4
benubacha at 2007-7-8 23:05:56 > top of Java-index,Enterprise & Remote Computing,Web Tier APIs...