Runnable Jar and multiple versions of java
<p>I sent a runnable jar to a friend.  He double clicks on it and it doens't open it crashes.  However my other friend can open it.</p>

<p>I believe the problem is that my first friend has multiple versions of java on their machine and it is using the wrong version on the double click.</p>

<p>How can I have the correct version of java be used to run my jar?  I am ok to have my friend do this from the command line.</p>
