Undefined index file1 $_FILES exception

PHP
1 
         echo '<form action="#" method="POST" enctype="multipart/form-data">';
         echo '<b>Upload a Image file</b>';
	echo '<input type="file" name="file1"/>';
	echo "<br>";
	echo'<input type="submit" name="submit" value="submit"/>'.PHP_EOL;
	echo '</form>'.PHP_EOL;


move_uploaded_file($_FILES['file1']['tmp_name'], '../files/'.$_FILES['file1']['name']);
```
2

What does print_r($_FILES) tell you about the contents of the array?