How can I apply jQuery.click only to first level elements?

Question

I need to apply jQuery.click only to first level elements. How to do it?

Here is my list:

<ul id="adminMenu">
  <li id="A">
    <h3><a href="">Item 1</a></h3>
  </li>
  <li id="B">
    <h3>Item 2</h3>
    <ul style="display: block;">
      <li id="a1"> Sub Item 1 </li>
      <li id="a2"> Sub Item 2 </li>
      <li id="a3"> Sub Item 3 </li>
    </ul>
  </li> 
  <li id="C">
    <h3>Item 3</h3>
    <ul style="display: none;">
      <li> Sub Item 4 </li>
      <li> Sub Item 5 </li>
    </ul>
  </li> 
</ul>

And here is jQuery

jQuery('#adminMenu > li').click(function(){
  alert('test');
});

UPDATE The
warning should not be when I click on a submenu item, only when I click on list items A, B or C.

SOLUTION 1
This is working code based on the Marxels proposal.

  jQuery('#adminMenu > li > h3').click(function(e) {
    var activeUL = jQuery("#adminMenu > li ul:visible");
    var activeLI = jQuery("#adminMenu > li ul:visible").parent('li:first');
    var clicked = jQuery(this).parent('li:first');
    // Close submenu
    activeUL.hide('fast');
    // Open submenu
    if( activeLI.attr('id') != clicked.attr('id') )        
      clicked.children('ul').show('fast');
  });

SOLUTION 2
This is a working code based on the proposal of the Century.

  jQuery('#adminMenu > li').click(function(e) {
      var clicked = jQuery(e.target);
      // Ensure we're checking which list item is clicked,
      // other children should be allowed
      if(!clicked.is('li') && clicked.parents('li').length > 0) {
          // :first ensures we do not select higher level list items
          clicked = clicked.parents('li:first');
      }
      // If clicked list item is a child of another list item, we'll exit here
      if(!clicked.is('#adminMenu > li')) {
          return;
      }
    var activeUL = jQuery("#adminMenu > li ul:visible");
    var activeLI = jQuery("#adminMenu > li ul:visible").parent('li:first');

    // Close submenu
    activeUL.hide('fast');
    // Open submenu
    if( activeLI.attr('id') != clicked.attr('id') )        
      clicked.children('ul').show('fast');
  });

Thanks guys! I would never have managed this without your help! :)

Answer 1

jQuery('#adminMenu > li').click(function(e) {
    var clicked = jQuery(e.target);
    // Ensure we're checking which list item is clicked,
    // other children should be allowed
    if(!clicked.is('li') && clicked.parents('li').length > 0) {
        // :first ensures we do not select higher level list items
        clicked = clicked.parents('li:first');
    }
    // If clicked list item is a child of another list item, we'll exit here
    if(!clicked.is('#adminMenu > li')) {
        return;
    }
    alert('test');
});

Updated to exit if the click list item is not an immediate child #adminMenu.

Answer 2

, LI ( ..). "" , :

jQuery("#adminMenu > li > h3").click(...);

Answer 3

Get a set of elements containing all the unique immediate children of each of the agreed set of elements.

children ([expr])

http://docs.jquery.com/Traversing/children

   jQuery('#adminMenu').children('li').children('h3').click(function()
   {  
       alert('test');
   });

Answer 4

jQuery('#adminMenu li:first').