page reloading

hi
when i am going to use so an so script as plugin

<?php
/*
plugin Name: admin Menu
plugin URI: http://wp-help.blogspot.com/
Description: Admin Menu
Author: **********
Author URI: http://wp-help.blogspot.com/
*/

//hook for adding admin menus
add_action(‘admin_menu’,’mt_add_pages’);
//action function for above hook
function mt_add_pages() {
//add a new top-level menu (ill-advised):
add_menu_page(_(‘your menu title’), _(’email client’), ‘manage_options’, ‘mt-top-level-handle’, ‘mt_toplevel_page’ );
}
function mt_toplevel_page() {
echo do_shortcode(‘[mailcwp]’);
}
?>

and activated plugin an when i am trying to open application that application is going on reloading or any button from plugin are not working can anybody help me how to slove the problem an stop reloading the application

https://wordpress.org/plugins/mailcwp/