# Calling a REST service from JavaScript
```js
fetch(
"https://localhost:5001/WeatherForecast?location=" + requestedLocation,
{
method: 'GET'
})
.then(response =>
{
...
})
.catch(err =>
{
this.Available = false;
this.Notice = "The following fatal error occurred while contacting the API: " + err;
});
```
- `fetch` is a JavaScript function which returns a Promise
- `then` is a bind for the Promise
If you're getting an error saying that the service is not usable due to a CORS policy and you're using ASP.NET Core, include the following code in your `Configure` method:
```csharp
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
app
.UseCors(builder =>
builder
.AllowAnyOrigin()
.AllowAnyHeader()
.AllowAnyMethod());
}
```
(not a good idea for an actual production app)