Add Extra Fields to WordPress user profile

wp_user-profile-fields.php

<?php 
/* Add Extra Profile Meta fields to WordPress user profile

*/

//Extra Author Profile Meta
add_action( 'show_user_profile', 'my_show_extra_profile_fields' );
add_action( 'edit_user_profile', 'my_show_extra_profile_fields' );
function my_show_extra_profile_fields( $user ) { ?>
	<h3>Is this an active author?</h3>
	<table class="form-table">
		<tr>
			<td>
				<?php $agree = get_the_author_meta( 'active_author', $user->ID ); ?>
				<label for="active_author">Active Author <input value="true" name="active_author" id="active_author" <?php if ($agree == 'true' ) { ?>checked="checked"<?php }?> type="checkbox" /></label>
			</td>
		</tr>
	</table>
<?php }
add_action( 'personal_options_update', 'my_save_extra_profile_fields' );
add_action( 'edit_user_profile_update', 'my_save_extra_profile_fields' );
function my_save_extra_profile_fields( $user_id ) {
	if ( !current_user_can( 'edit_user', $user_id ) )
		return false;
	/* Copy and paste this line for additional fields. Make sure to change 'active_author' to the field ID. */
	update_usermeta( $user_id, 'active_author', $_POST['active_author'] );
}

?>