Compiling JAR with LOWER version of java?

[nhmllr]

I programmed a little helpful program with the 64-bit Java 6.0 on a computer running Windows-7
There's nothing in the program that would restrict it from running on my mac, which is what I'm trying to do now
(The JAR works fine on my PC)

The thing is that my mac is a little old, and even with the newest version available (that I could find for it) I still get this:

Exception in thread "main" java.lang.UnsupportedClassVersionError: Bad version number in .class file
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:675)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
	at java.net.URLClassLoader.access$100(URLClassLoader.java:56)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:316)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:280)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
	at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:374)

Which I think means that I compiled the JAR in a higher version than I'm running it.
There's nothing super-advanced about my program, I'm sure it could run fine in lower versions.

Is there a way to actually compile it with a lower version of Java so that it can run on more machines?

Thanks!

By the way, I'm running Mac OS X 10.5.8
This is the update I used:
Java for Mac OS X 10.5 Update 4
And here's what my mac says it's running, but I can't tell if it's the same thing, or the right thing

java version "1.5.0_20"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_20-b02-315)
Java HotSpot(TM) Client VM (build 1.5.0_20-141, mixed mode, sharing)

[nhmllr]

Okay, the funniest thing. It turns out that even if you HAVE Java 6.0 on your mac it won't run until you physically DRAG it to the top of a list
This list can be found be searching for "Java Preferences" and seeing a little list of all the versions. Drag Java 6.0 to the top

But if anyone knows how to compile in lower versions I'd still like to know :p

[DarrylBurke]

javac -target ...
javac - Java programming language compiler

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