phantom.casperPath = 'path/to/node_modules/casperjs';
phantom.injectJs('path/to/node_modules/casperjs/bin/bootstrap.js');

phantom.casperTest = true; 


//var casper = require('casper'); 
var x = require('casper').selectXPath; 

casper.start('http://google.com/', function() {
	this.echo(this.getTitle());
	this.assertExists(x('//*[@id="gbqfbb"]'), 'the element exists');  
}); 

casper.run();