Java DOM - Inserting an element, after another

Given the following XML file:

<?xml version="1.0" encoding="UTF-8"?>
<process
    name="TestSVG2"
    xmlns="http://www.example.org"
    targetNamespace="http://www.example.org"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema">
   <sequence>
      <receive name="Receive1" createInstance="yes"/>
      <assign name="Assign1"/>
      <invoke name="Invoke1"/>
      <assign name="Assign2"/>
      <reply name="Reply1"/>
   </sequence>
</process>

I want to add a new element inside the <sequence></sequence> after a certain pre-existing element. For example if I want to add the node after "Assign1", the new XML should like this:

   <sequence>
      <receive name="Receive1" createInstance="yes"/>
      <assign name="Assign1"/>
      <newtype name="NewNode"/>
      <invoke name="Invoke1"/>
      <assign name="Assign2"/>
      <reply name="Reply1"/>
   </sequence>

I have to do this by using Java DOM, in a function. The function signature should like this:

 public void addActionDom(String name, String stepType, String stepName)

Where:

• name is the pre-existing element, after which the insertion will be made;
• stepType is the inserted element type;
• stepName is the name attribute of the newly inserted element.

Currently I am lacking experience with JDOM, or any other Java XML library. Can you please give a sample code, or point me to a tutorial where an insertion after a certain element is made.

This is the code I have until now:

    public void addActionDom(String name, String stepType, String stepName) {
        File xmlFile = new File(path + "/resources/" + BPELFilename);
        DocumentBui