public function assignValue ( $propNameOrig, $propValue ) {
        $propNameA = str_replace( self::$replaceChars, '_', $propNameOrig );
        $propName = preg_replace( "/[^A-Za-z0-9_]/", "", $propNameA );
        if (property_exists( $this, $propName ) && $this->$propName !== NULL) {
            $this->assignExisting( $propName, $propValue );
        } elseif ($propName !== '') {
            $this->$propName = $propValue;
        }
    }