Notice: Undefined index: img1 in >>>>>> how to remove that error

Notice: Undefined index: img1 in >>>>>> how to remove that error. i tried to upload file to particular directory. but there are errors. file does note moving.

<form method="POST" action="" enctype="multipart/form-data">
      <input type="file" name="img1">
      <input type="submit" value="Submit">
      </form>
       <?php
    $name= $_FILES['img1']['name'];

    $tmp_name = $_FILES['$name']['tmp_name'];

    if (isset($name)) {
    if (!empty($name)){
    $location = 'gallery/gallery-image/';

    if (move_uploaded_file($tmp_name,'gallery/gallery-image/1.jpg')){
        echo 'Uploaded';
    }
    }else{
        echo 'please choose a file';
    }
    }
     ?>