cannot access to this of component in subscribe function
<p>I'm trying navigate to new page when get answer from server:</p>

<pre><code>import {Component} from '../../node_modules/angular2/core';
import {Router} from "../../node_modules/angular2/router";
import {Http, Headers, HTTP_PROVIDERS} from '../../node_modules/angular2/http'

@Component({
    selector: 'test-page',
    templateUrl:'src/login/test.html',
    providers: [HTTP_PROVIDERS]
})


export class TestPage {
    constructor(private _router:Router,
                private _http:Http) {
    }

    Test(username, password) {
        let body = 'test';
        let headers = new Headers();
        headers.append('Content-Type', 'application/x-www-form-urlencoded');
        this._http.post('/api/test', 'test', {headers: headers})
        .subscribe(
                response =&gt; {
                    this._router.navigateByUrl('Home'); //'this' is not a component
                },
                error =&gt; {
                   console.log(error)
                }
       );
     }
}
</code></pre>

<p>But by some reason 'this' is not a pointer to component but it's a subscribe.
Does someone know the reason of issue?</p>