Function to add custom fields in Wordpress user profile editor

functions.php

/**
* Function to display custom field in Admin Profile editor
* Only Admin can view these options
*/
function user_custom_fields($user) {
	if (is_admin()) { // Check of admin
		$is_verified = get_the_author_meta('is_verified', $user->ID);
		$is_qualified = get_the_author_meta('is_qualified', $user->ID);
		
?>		<table class="form-table">
			<tr>
				<th><label for="is_verified">Verified?</label></th>
				<td><input id="is_verified" type="checkbox" name="is_verified" <?php echo $is_verified ? 'checked="checked"' : ''; ?> /></td>
			</tr>
			<tr>
				<th><label for="is_qualified">Qualified?</label></th>
				<td><input id="is_qualified" type="checkbox" name="is_qualified" <?php echo $is_qualified ? 'checked="checked"' : ''; ?> /></td>
			</tr>
		</table>
<?php
	}
}

/**
 * Function to save options
 */
function save_user_custom_fields($user_id) {
	if (!current_user_can('edit_user', $user_id)) {
		return false;
	}

	update_user_meta($user_id, 'is_verified', ($_POST['is_verified'] ? true : false));
	update_user_meta($user_id, 'is_qualified', ($_POST['is_qualified'] ? true : false));
}

add_action('show_user_profile', 'user_custom_fields');
add_action( 'edit_user_profile', 'user_custom_fields' );
add_action( 'edit_user_profile_update', 'save_user_custom_fields' );
add_action( 'personal_options_update', 'save_user_custom_fields' );