(no version information, might be only in CVS)
DomDocument->get_element_by_id -- 
     Searches for an element with a certain id
    
Description
domelement 
DomDocument->get_element_by_id ( string id )
     This function is similar to
     domdocument_get_elements_by_tagname() 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, though the current
     implementation simply does an xpath search for "//*[@ID = '%s']". This
     does not comply to the DOM standard which requires to return null if it
     is not known which attribute is of type id. This behaviour is likely to
     be fixed, so do not rely on the current behaviour.
    
     See also domdocument_get_elements_by_tagname()