I have some source codes from a friend that I would like to use as referenced library in my BlackBerry project. I'm not sure about how to package the source codes into a .jar file. I tried exporting the source to a JAR file and import it as external JAR in my project, it's giving me missing stack map error. I tried to preverify the .jar file generated from the source using the provided preverification tool from BlackBerry JDE, it didn't give me any output folder. In fact, I'm not sure if the way I export the source is correct. Can anyone provide step-by-step instructions on how to package existing source code into a valid JAR file that can be imported into my project as a referenced library? Again, I'm using eclipse. Thanks very much in advance.