function clear($key) {
		if (array_key_exists($key,$this->adhoc))
			unset($this->adhoc[$key]);
		else
			unset($this->props[$key]);
	}
function clear($key) {
		if (array_key_exists($key,$this->adhoc))
			unset($this->adhoc[$key]);
		else
			unset($this->props[$key]);
	}
function clear ( $ key ) { if ( array_key_exists ( $ key , $ this -> adhoc ) ) unset ( $ this -> adhoc [ $ key ] ) ; else unset ( $ this -> props [ $ key ] ) ; }
Clear value of field
@return NULL
@param $key string
Clear value of field