title: Simple swing application. The jar file runs on my computer, but not others
body: <p>This is my first question, so apologies for any mistakes. I'll try and give all the info I can. Basically I've written a simple swing application which just loads in image into a JPanel and displays it. I'm using Netbeans 7.1 and I have the latest version of the Java SDK. 
  Anyway, I've used the "Build" feature in NetBeans 7.1 to deploy my application into a Jar file. When I double click the Jar File on my PC, it runs without a problem. However when I put it on other computers (Tested on 2 others so far, both with the most current JRE) it fails to open, citing the following error: </p>
  
  <blockquote>
    <p>could not find the main class: swong.Startup. Program will exit</p>
  </blockquote>
  
  <p>swong is my package name, and Startup is the location of my main method. I have checked the manifest file which is created with Netbeans' build, and it[the manifest] does indeed contain the location of my main method class.</p>
  
  <p>From searching, I've come across similar issues in which the classpath is set wrongly, but I don't understand how this could cause my particular error.</p>
  
  <p>If someone could help me, I would be over the moon. I've been studying java for a year or so, and I've got a good handle down, but I've NEVER been able to make a Jar that runs on a computer which wasn't my own. So, 10 points and thanks in advance.</p>
  
  <p>xo.</p>
  
  <p>EDIT: Thank you for the responses. I'm doing shift work and swamped, but I will test and poke with these responses tomorrow and provide more information. Thanks again. xo</p>