function Show_menu_list( menu_id ) 
 {
  var menu = document.getElementById( menu_id );
  if ( menu ) { menu.style.display = 'block'; }	
 }
 
function Hide_menu_list( menu_id )
 {
  var menu = document.getElementById( menu_id );
  if ( menu ) { menu.style.display = 'none'; }	
 }
function  Hide_all_menu_list(  )
 {
  var products_menu_list = document.getElementById( "products_menu_list" );
  var projects_menu_list = document.getElementById( "projects_menu_list" );
  var about_us_menu_list = document.getElementById( "about_us_menu_list" );
  var blog_menu_list = document.getElementById( "blog_menu_list" );
  var contact_menu_list = document.getElementById( "contact_menu_list" );

  if ( products_menu_list ) { products_menu_list.style.display = 'none'; }	
  if ( projects_menu_list ) { projects_menu_list.style.display = 'none'; }	
  if ( about_us_menu_list ) { about_us_menu_list.style.display = 'none'; }	
  if ( blog_menu_list ) { blog_menu_list.style.display = 'none'; }	
  if ( contact_menu_list ) { contact_menu_list.style.display = 'none'; }	
 }