Run-time error in constructor

Hello,

My program shown below has the following run-time errror:

Object reference not set to an instance of an object.
Use the "new" keyword to create an object instance.

when I call

Net netObj = new Net(n_layers);

in InitNetwork(). The run-time error is in the constructor at the line:

Layer[k] = new Layer(n_layers, ni, nh, no);

My program is:

using System;
using System.Collections.Generic;
using System.Text;

namespace Test {
class Program {
static int n_layers = 3;
static int ni = 30;
static int nh = 10;
static int no = 1;

public class Layer {
public int Units;
public double[] Output;
public double[] Error;
public Layer(int n_layers, int ni, int nh, int no) {
Units = 0;
Output = new double[n_layers];
Error = new double[n_layers];
}
};

public class Net {
public Layer[] Layer = null;
public double Alpha;
public Net(int n_layers) {
for (int k=0; k<n_layers; k++) {
Layer[k] = new Layer(n_layers, ni, nh, no);
}
Alpha = 0.0;
}
};

void InitNetwork() {
Layer[] layerObj = new Layer[n_layers];
for (int k=0; k<n_layers; k++) {
layerObj[k] = new Layer(n_layers, ni, nh, no);
}
Net netObj = new Net(n_layers);
netObj.Alpha = 0.9;
}

static void Main(string[] args) {
Program testObj = new Program();
testObj.InitNetwork();
}
}
}

Any help will be greatly appreciated.

Charles

[2424 byte] By [CBrauer] at [2008-1-10]