$flags= ENT_COMPAT | ENT_HTML401 [, string
$encoding= 'UTF-8' ]] )
html_entity_decode() is the opposite of
that it converts all HTML entities
string to their applicable characters.
More precisely, this function decodes all the entities (including all numeric entities) that a) are necessarily valid for the chosen document type — i.e., for XML, this function does not decode named entities that might be defined in some DTD — and b) whose character or characters are in the coded character set associated with the chosen encoding and are permitted in the chosen document type. All other entities are left as is.