Listing all nodes from a xml sheet

Alo all

Ive got an xml sheet that is 3 levels deep (part example below)

   <navItem itemName="1" itemPath="" itemClip="">
          <navItem itemName="1.1" itemPath="" itemClip="">
               <navItem itemName="1.1.1" itemPath="" itemClip=""/>
               <navItem itemName="1.1.2" itemPath="" itemClip=""/>
               <navItem itemName="1.1.3" itemPath="" itemClip=""/>
               <navItem itemName="1.1.4" itemPath="" itemClip=""/>
          <navItem itemName="1.2" itemPath="" itemClip="">
          <navItem itemName="1.3" itemPath="" itemClip="">
          <navItem itemName="1.4" itemPath="" itemClip="">
               <navItem itemName="1.4.1" itemPath="" itemClip=""/>

That i want to read into an array in sequental order.

At the moment i can only get the first level showing up with the following code:

var menuItems = this.firstChild;
		for (var i = 0; i<menuItems.childNodes.length; i++) {

How would i go about adding the rest of the nodes into the array?