(no version information, might be only in CVS)
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.