title: NSXMLParser example
body: <p>I have an XML like this</p>
  
  <pre><code>&lt;IS&gt;
      &lt;Value&gt;
          &lt;Signature&gt;-804&lt;/Signature&gt;
          &lt;Amount&gt;139&lt;/Amount&gt;
      &lt;/Value&gt;
      &lt;Value&gt;
          &lt;Signature&gt;-845&lt;/Signature&gt;
          &lt;Amount&gt;639466&lt;/Amount&gt;
      &lt;/Value&gt;
      &lt;Value&gt;
          &lt;Signature&gt;-811&lt;/Signature&gt;
          &lt;Amount&gt;16438344&lt;/Amount&gt;
      &lt;/Value&gt;
      &lt;Value&gt;
          &lt;Signature&gt;-1115&lt;/Signature&gt;
          &lt;Amount&gt;-159733&lt;/Amount&gt;
      &lt;/Value&gt;
  &lt;/IS&gt;
  </code></pre>
  
  <p>Now I want to parse only specific values from this. 
  For example, how do I get the  value for the node having corresponding signature as -804</p>
  
  <p>Please help me..</p>
  
  <p>I know the basics of NSXMLParser, but do not know how to acheive conditional parsing.</p>
  
  <p>Thank you.</p>