PHP - Undefined index: id

<table class="table-bordered">

    <thead>

        <tr>

            <th scope="col" style="text-align: center">#</th>

            <th scope="col" style="text-align: center">Name</th>

            <th scope="col" style="text-align: center">Email</th>

            <th scope="col" style="text-align: center">Password</th>

            <th scope="col" style="text-align: center">remember_token</th>

            <th scope="col" style="text-align: center">created_at</th>

            <th scope="col" style="text-align: center">updated_at</th>

            <th scope="col" style="text-align: center">Acciones</th>

        </tr>

    </thead>

    <tbody>

        @foreach($registers as $register)

        <tr>

            <th class="col" style="width: auto" scope="col">{!! $register->id !!}</th>

            <th class="col" style="width: auto" scope="col">{!! $register->name !!}</th>

            <th class="col" style="width: auto" scope="col">{!! $register->email !!}</th>

            <th class="col" style="width: auto" scope="col">{!! $register->password !!}</th>

            <th class="col" style="width: auto" scope="col">{!! $register->remember_token !!}</th>

            <th class="col" style="width: auto" scope="col">{!! $register->created_at !!}</th>

            <th class="col" style="width: auto" scope="col">{!! $register->updated_at !!}</th>

            <th class="col" style="width: auto" scope="col">

                <p><a href="delete_register.php?id={!! $register->id !!}">Borrar</p></a>

                <p><a href="edituser?id={!! $register->id !!}">Editar</p></a>

            </th>

        </tr>

        @endforeach

    </tbody>

</table>

<?php

    use Illuminate\Support\Facades\DB;

    $id= $_GET["id"];

    DB::delete('DELETE FROM users where id = ?', [1, $id]);

?>