add example

examples/NetworkMonitor.js

@@ -0,0 +1,29 @@
+'use strict';
+
+var run = function() {
+  // Replace '../bitcore' with 'bitcore' if you use this code elsewhere.
+  var bitcore = require('../bitcore');
+  var NetworkMonitor = bitcore.NetworkMonitor;
+
+  var config = {
+    networkName: 'testnet',
+    host: 'localhost',
+    port: 18333
+  };
+
+
+  var nm = new NetworkMonitor.create(config);
+  // monitor incoming transactions to http://tpfaucet.appspot.com/ donation address
+  nm.incoming('msj42CCGruhRsFrGATiUuh25dtxYtnpbTx', function(tx) {
+    console.log('Donation to tpfaucet! '+JSON.stringify(tx.getStandardizedObject()));
+  });
+
+  // connect to bitcoin network and start listening
+  nm.start();
+
+};
+
+module.exports.run = run;
+if (require.main === module) {
+  run();
+}