Understanding Classpaths when creating externals in Eclipse w toxi Libs

Hey,

I am relatively inexperienced Java person, I usually work with Processing and avoid Eclipse, but I have created a few max externals previously. I haven't, however, created any mxj objects that use external libraries.

I thought I followed the process correctly. I believe I have imported the libraries correctly into my java project in eclipse (toxi libs). I am not getting any errors, put it that way, but when I try and run the object in max I get this error.

java.lang.NoClassDefFoundError: toxi/physics2d/behaviors/ParticleBehavior2D

I believe this is a class path thing? Perhaps max doesn't know where to find the verletphysics.jar ?

My class is below. Essentially I am wanting to use toxi physics to augment imput - at the present it is obviously not doing that - I was just testing the concept , which didn't work!! The class is based on Toxi's example.

Any help much appreciated.

import com.cycling74.max.*;

import toxi.geom.*;
import toxi.physics2d.*;
import toxi.physics2d.behaviors.*;

public class toxiPart extends MaxObject {

    int NUM_PARTICLES = 1;

    VerletPhysics2D physics;
    AttractionBehavior mouseAttractor;
    Vec2D mousePos;

    public toxiPart(){

         physics = new VerletPhysics2D();
         physics.setDrag(0.05f);
         physics.setWorldBounds(new Rect(0, 0, 200, 200));

         //set attractor
         mousePos = new Vec2D(100, 100);
         // create a new positive attraction force field around the mouse position (radius=250px)
         mouseAttractor = new AttractionBehavior(mousePos, 1000, 0.9f);
         physics.addBehavior(mouseAttractor);

         declareInlets(new int[]{ DataTypes.ALL, DataTypes.ALL});
     declareOutlets(new int[]{ DataTypes.ALL, DataTypes.ALL});

    }

    void addParticle() {
         VerletParticle2D p = new VerletParticle2D(Vec2D.randomVector().scale(5).addSelf(200 / 2, 0));
         physics.addParticle(p);
         // add a negative attraction force field around the new particle
         //physics.addBehavior(new AttractionBehavior(p, 20, -1.2f, 0.01f));
        }

    public void bang(){

        if (physics.particles.size() < NUM_PARTICLES) {
         addParticle();
         }

        mousePos.set((float)Math.random()*200, (float)Math.random()*200);
         physics.update();

         for (VerletParticle2D p : physics.particles) {
         outlet(0,p.x);
         outlet(1,p.y);
         }

    }

}