# Checking the usability of your key

Your key may not be available at some times. For instance:

Your key may have reached its daily cap set by you Your user has reached their individual usage cap for the day The balance on your key is exhausted By default, Address Lookup will not initialize if your key is not usable for whatever reason. You may use the [`onLoaded`](https://address-finder.ideal-postcodes.co.uk/interfaces/controller.controlleroptions.html#onLoaded) and [`onFailedCheck`](https://address-finder.ideal-postcodes.co.uk/interfaces/controller.controlleroptions.html#onFailedCheck) callbacks to make necessary adjustments.

To disable key checking, set `checkKey` to `false`.

Loading...

```
<form>
<p id="message"></p>
<label for="input">Search Your Address</label>
<input type="text" id="input" placeholder="Start typing address here" />
<label for="line_1">Address First Line</label>
<input type="text" id="line_1" />
<label for="line_2">Address Second Line</label>
<input type="text" id="line_2" />
<label for="city">City</label>
<input type="text" id="city" />
<label for="state">State</label>
<input type="text" id="state" />
<label for="zipcode">Zip Code</label>
<input type="text" id="zipcode" />
</form>
```

```

import { AddressLookup } from "@addresszen/address-lookup";

AddressLookup.setup({
  inputField: "#input",

  // Test key: 'ak_test' passes the check
  apiKey: "ak_test",
  // Test key: 'ak_fails' fails the key check
  // apiKey: 'ak_fails',

  // By default, checkKey is enabled
  checkKey: true,

  // Invoked if plugin loads
  onLoaded: function () {
    const el = document.getElementById("message");
    el.textContent = "Check passed! Start typing your address";
    el.className = "success";
  },

  // Invoked if key fails check
  onFailedCheck: function () {
    const el = document.getElementById("message");
    el.textContent = "Check failed. Please manually enter your address";
    el.className = "error";
  },

  outputFields: {
    line_1: "#line_1",
    line_2: "#line_2",
    city: "#city",
    state: "#state",
    zip_plus_4_code: "#zipcode",
  },
});
```

```

#message {
  margin: 0 0 0.5rem;
  padding: 0.5rem 0.75rem;
  font-size: 0.8125rem;
  font-weight: 500;
  border-radius: 0.375rem;
}
#message:empty {
  display: none;
}
#message.success {
  color: #065f46;
  background-color: #d1fae5;
  border: 1px solid #a7f3d0;
}
#message.error {
  color: #991b1b;
  background-color: #fee2e2;
  border: 1px solid #fecaca;
}
[data-theme="dark"] #message.success {
  color: #6ee7b7;
  background-color: rgba(16, 185, 129, 0.12);
  border-color: rgba(110, 231, 183, 0.35);
}
[data-theme="dark"] #message.error {
  color: #fca5a5;
  background-color: rgba(239, 68, 68, 0.12);
  border-color: rgba(252, 165, 165, 0.35);
}
```