title: parsing xml file and its elements in R
body: <p>I am trying to parse a XML file that has the following structure</p>
  
  <pre><code> &lt;xs:schema attributeFormDefault="qualified" elementFormDefault="qualified" targetNamespace="http://12345hc.com/xsd"&gt;
              &lt;xs:complexType name="Context"&gt;
                  &lt;xs:sequence&gt;
                      &lt;xs:element minOccurs="0" name="aNum" nillable="true" type="xs:string"/&gt;
                      &lt;xs:element minOccurs="0" name="aId" nillable="true" type="xs:string"/&gt;
                      &lt;xs:element minOccurs="0" name="bURI" nillable="true" type="xs:string"/&gt;
                      &lt;xs:element minOccurs="0" name="facility" nillable="true" type="xs:string"/&gt;
                      &lt;xs:element minOccurs="0" name="fSessionId" nillable="true" type="xs:string"/&gt;
                      &lt;xs:element minOccurs="0" name="ID" nillable="true" type="xs:string"/&gt;
                      &lt;xs:element minOccurs="0" name="pwrd" nillable="true" type="xs:string"/&gt;
                      &lt;xs:element minOccurs="0" name="profileID" nillable="true" type="xs:string"/&gt;
                      &lt;xs:element minOccurs="0" name="sToken" nillable="true" type="xs:string"/&gt;
                      &lt;xs:element minOccurs="0" name="sId" nillable="true" type="xs:string"/&gt;
                      &lt;xs:element minOccurs="0" name="tId" nillable="true" type="xs:string"/&gt;
                      &lt;xs:element minOccurs="0" name="uNum" nillable="true" type="xs:string"/&gt;
                      &lt;xs:element minOccurs="0" name="webURI" nillable="true" type="xs:string"/&gt;
                      &lt;xs:element minOccurs="0" name="xZRT" nillable="true" type="xs:string"/&gt;
                  &lt;/xs:sequence&gt;
              &lt;/xs:complexType&gt;
          &lt;/xs:schema&gt;
  </code></pre>
  
  <p>I trying to select the node having <code>name="Context"</code> tag, </p>
  
  <p>within this tag select the element labeled as ID,<br>
  <code>&lt;xs:element minOccurs="0" name="ID" nillable="true" type="xs:string"/&gt;</code> </p>
  
  <p>and add value "111111" to this element <code>ID</code>. </p>
  
  <p>Any pointers/answers on accomplishing this will be very helpful. Thanks in advance.</p>