xml not retrived by javascript

This may seem too trivial but I have tried all possible methods

1. async=true (onreadystatechange)
2. async=false (xmlhttp open)

source http://ift.tt/ZxhTtu

3.xmlhttp.open("GET","http://"+location.host+"/cd_catalog.xml",false)

source

Open XML and display data in div

basically what I want is for javascript and xml in the same folder and use javascript to return values.

The actual program I am working on:

var xmlSolver = function MakeXmlSolver(){};
xmlSolver.GetAllAuthorsInStock()=function()
{
var author=xmlDoc.getElementsByTagName   
    ("author").childNodes.nodeValue;

return author;
 };

   xmlSolver.GetAllBooksInStock()=function()
   {
var title=xmlDoc.getElementsByTagName
     ("title").childNodes.nodeValue;
     }

and the xml

<?xml version='1.0'?>
<!-- This file represents a fragment of a book store inventory database -->
<bookCollection>
  <book genre="philosophy" publicationdate="1991" ISBN="1-861001-57-6">
    <title>The Gorgias</title>
    <author>
      <name>Plato</name>
    </author>
    <price>9.99</price>
  </book>
  <book genre="autobiography" publicationdate="1981" ISBN="1-861003-11-0">
    <title>The Autobiography of Benjamin Franklin</title>
    <author>
      <firstName>Benjamin</firstName>
      <lastName>Franklin</lastName>
    </author>
    <price>8.99</price>
  </book>
  <book genre="novel" publicationdate="1967" ISBN="0-201-63361-2">
    <title>The Confidence Man</title>
    <author>
      <firstName>Herman</firstName>
      <lastName>Melville</lastName>
    </author>
    <price>11.99</price>
  </book>
  <book genre="novel" publicationdate="2002" ISBN="0-201-63361-2">
    <title>Oryx and Crake</title>
    <author>
      <firstName>Margaret</firstName>
      <lastName>Atwood</lastName>
    </author>
    <price>11.99</price>
  </book>
  <book genre="philosophy" publicationdate="1991" ISBN="1-861001-57-6">
    <title>The Republic</title>
    <author>
      <name>Plato</name>
    </author>
    <price>7.99</price>
  </book>
</bookCollection>