WordPress at a glance
function is not described

wp_ajax_update_welcome_panel() WP 3.1.0

Ajax handler for updating whether to display the welcome panel.

No Hooks.

Return

Nothing (null).

Usage

wp_ajax_update_welcome_panel();

Code of wp ajax update welcome panel: wp-admin/includes/ajax-actions.php VER 5.0.3

<?php
function wp_ajax_update_welcome_panel() {
	check_ajax_referer( 'welcome-panel-nonce', 'welcomepanelnonce' );

	if ( ! current_user_can( 'edit_theme_options' ) )
		wp_die( -1 );

	update_user_meta( get_current_user_id(), 'show_welcome_panel', empty( $_POST['visible'] ) ? 0 : 1 );

	wp_die( 1 );
}