Cannot get IDEA to see JAR file when running simple Java Application from IDE

I have a simple Java application where I'm trying to read a file in a JAR  file like this:

InputStream inputStream = classLoader.getResourceAsStream("resource.properties");

This "resource.properties" is in a JAR file.

Trying to run this program standalone in IDEA, even with the JAR  file in the "src" folder does not work since the jar file is not  specifically mentioned.

To run this code at the command line (not using IDEA IDE), I'd first set the CLASSPATH like this:

CLASSPATH=.:resources.jar
export classpath

Then, it works (at the command line, without IDEA IDE)

---

OK, so my IDEA question is how do I make IDEA aware of this JAR file so the code will run within the IDE?

I've tried putting the JAR file in the dependencies tab as a JAR and  also tried to "export" it. But running this program in IDEA always  gives the NullPointerException since it can't find the JAR.

Then I also put the jar file as a library entry in IDEA.

NullPointerExceptions each time.

What's the trick to specify a JAR file (call it "resources.jar") in IDEA (13.0.1) so it will be recognized by IDEA?

Thanks,
m