Property 'mybooking' does not exist on type 'AuthService'. Did you mean 'booking'?

I get this error when i try to load page.

src/account/account.ts

import { Component } from ‘@angular/core’;
import { IonicPage, NavController, NavParams } from ‘ionic-angular’;
import { AuthService } from ‘…/…/providers/auth-service/auth-service’;
/**

@IonicPage()
@Component({
selector: ‘page-account’,
templateUrl: ‘account.html’,
providers: [AuthService]
})
export class AccountPage {

bookings: any;

constructor(public navCtrl: NavController, public navParams: NavParams, public authService: AuthService) {

this.mybooking();

}

mybooking(){

this.authService.mybooking().subscribe((data)=>{
this.bookings = data;
});

}


auth-service.ts

@Injectable()
export class AuthService {

constructor(public http: Http) {}

mybooking() {
return new Promise((resolve, reject) => {
let headers = new Headers();
headers.append(‘Content-Type’, ‘application/json’);

    this.http.get(mybookingurl, JSON.stringify(data), {headers: headers})
      .subscribe(res => {
        resolve(res.json());
      }, (err) => {
        reject(err);
      });
});

}