XML : How to get an XML Tag belonging to another tag with specific attribute in Java?

I want to get a tag from another tag specified with an attribute I have chosen. In this XML file for example, how do I proceed to print the mark 85 of the student 393?

  <?xml version="1.0"?>  <class>  <student rollno="393">    <firstname>dinkar</firstname>    <lastname>kad</lastname>    <nickname>dinkar</nickname>    <marks>85</marks>  </student>  <student rollno="493">    <firstname>Vaneet</firstname>    <lastname>Gupta</lastname>    <nickname>vinni</nickname>    <marks>95</marks>  </student>  <class>    

I am writing in Java and using JDom as follows

   NodeList nList = doc.getElementsByTagName("student");       for (int temp = 0; temp < nList.getLength(); temp++) {          Node nNode = nList.item(temp);          System.out.println("\nCurrent Element :" + nNode.getNodeName());           Element eElement = (Element) nNode;          System.out.println("Student roll no : " + eElement.getAttribute("rollno"));          System.out.println("First Name : "+ eElement.getElementsByTagName("firstname").item(0).getTextContent());          System.out.println("Last Name : " + eElement.getElementsByTagName("lastname").item(0).getTextContent());          System.out.println("Nick Name : "+ eElement.getElementsByTagName("nickname").item(0).getTextContent());          System.out.println("Marks : " + eElement.getElementsByTagName("marks").item(0).getTextContent());        }    

Thank you!