Can we use jdk7 javac to compile code with java7 functions in java6 bytecode

I considered the question of whether a java project can create 2 jars: one for java7 and one for java6, yes, the source code can use some some new functions of java7.

so to generate java6 jar command line will look like this:

javac -target 1.6 -bootclasspath jdk1.6.0\lib\rt.jar -extdirs "" MyApp.java

Unfortunately, He just emits an error:

javac: target release 1.6 conflicts with default source release 1.7

According to this document , it should be possible for jdk6 vs jdk5, does anyone know why it does not work in jdk7 vs jdk6? Am I doing something wrong or is it officially not officially supported?

Thank.