title: Error: The prefix "xsd" for element "xsd:schema" is not bound
body: <p>I'm extremely new to XML, and currently ready Ineasysteps.
  I keep getting the same issue from the parser saying </p>
  
  <blockquote>
    <p>5:The prefix "xsd" for element "xsd:schema" is not bound.</p>
  </blockquote>
  
  <p>This is the hello.xml:</p>
  
  <pre><code>&lt;?xml version = "1.0" encoding = "UTF-8" ?&gt;
  
  &lt;!-- XML in easy steps - Page 82. --&gt;
  
  &lt;doc xmlns:xsi=
  "http://www.w3.org/2001/XMLSchema-instance" 
  xsi:noNamespaceSchemaLocation = "hello.xsd" &gt;
  
  &lt;msg&gt;Hello World&lt;/msg&gt;
  
  &lt;/doc&gt;
  </code></pre>
  
  <p>Here is the hello.xsd doc</p>
  
  <pre><code>&lt;?xml version="1.0" encoding = "UTF-8" ?&gt;
  
  &lt;!-- XML in easy steps - Page 84. --&gt;
  
  &lt;xsd:schema&gt;
  
  &lt;!-- DECLARE ELEMENTS. --&gt;  
  
  &lt;!-- Simple types. --&gt;
  &lt;xsd:element name="msg" type="xsd:string"/&gt;
  
   &lt;!-- Complex types. --&gt;
   &lt;xsd:element name="doc" type="docType"/&gt;
  
  &lt;!-- DEFINE STRUCTURE. --&gt;
  
  &lt;xsd:complexType name="docType"&gt;
  &lt;xsd:sequence&gt;
      &lt;xsd:element ref="msg"/&gt;
  &lt;/xsd:sequence&gt;
  &lt;/xsd:complexType
  </code></pre>