How to create a main menu with dropdown? I want to create a main menu with dropdown. There will be collapsed links in each menu heading. When the user hovers over one heading, links accompanied by that header will be displayed in a box.

I first tried to add node and give them parent nodes. For example, I have created a node with title called "Lorem" and created another with title called "Ipsum". I have provided both of them a menu link. I have set the "Lorem" node as the parent node of "Ipsum". But it seems like "Ipsum" doesn't appear in "Lorem"'s content of its menu link.

Is there any way to look up the links' child elements? For example:

dpm($main_menu);


This doesn't yeild me neither the link that connected to "Ipsum" or the "Lorem"'s child links. How can I see the "Lorem"'s child link? Or where it is?

If I can find it, I can override the theme_links and create dropdowns.
You need to use any of this module

Nice Menus


  Nice Menus enables drop-down/right/left expandable menus. It uses only
  CSS for most browsers, with minimal Javascript for IE6.


Superfish Menu


  You will see several blocks called Superfish", move any of them to a
  region, use the "Configure" link of the block to configure it
  accordingly to your needs, and save.


Responsive Dropdown Menus


  
    Responsive Dropdown Menus provides a new menu tree rendering to make
    responsive, drop-down enabled main menu possible on any theme.
  

Provides new menu blocks for each menu.
All module blocks add dropdown menu support and responsive menu toggles.



Megamenu


  Mega menus are a type of drop-down, which seeks to overcome some of
  the usability drawbacks of traditional drop-downs. Hierarchy of your
  navigation is made visible all at once and the amount of clicking,
  searching, and navigating is reduced.