function mwpVerticalMenu2ToggleSub(li_object)
{
	//we get the index of the string selected_main_menu_item in the class name
	li_index_of_selected_class=li_object.parentNode.className.indexOf('selected_main_menu_item');

	//if selected_main_menu_item isn't in the string, then we need to put it in. If it is in the string, we need to remove it.
	if(li_index_of_selected_class==-1)
	{
		li_object.parentNode.className=li_object.parentNode.className+' selected_main_menu_item';
	}
	else
	{
		li_object.parentNode.className=li_object.parentNode.className.replace('selected_main_menu_item','');
	}

}