[Rirre]

No need to use set_task().

Just use menu_display( id , menu , 10 );
http://amxmodx.org/api/newmenus/menu_display

EDIT: Or do you want to destroy the menu after 10 seconds when the plugin has initialized?
An idea is to decrease a variable and use menu_display( id, menu, gTime ) in client_putinserver( id )