DOMDocument->getElementById()
DOMDocument->getElementById() -- Searches for an element with a certain id
Description
class 
DOMDocument { 
DOMElement 
getElementById ( string elementId )
}
   This function is similar to
   DOMDocument->getElementsByTagName() but 
   searches for an element with a given id.
  
   According to the DOM standard this requires a DTD which defines the 
   attribute ID to be of type ID. You need to validate your document with
   DOMDocument->validate() 
   or DOMDocument->validateOnParse before using this function.
  
Parameters
   
- elementId
- 
       The unique id value for an element.
       
Return Values
   Returns the DOMElement or NULL if the element is
   not found. 
  
Examples
| Example 1. DOMDocument->getElementById() Example | 
<?php
 $doc = new DomDocument;
 
 // We need to validate our document before refering to the id
 $doc->validateOnParse = true;
 $doc->Load('book.xml');
 
 echo "The element whose id is books is: " . $doc->getElementById('books')->tagName . "\n";
 
 ?>
 | 
 The above example will output: | The element whose id is books is: chapter | 
 |