function _md5($var) {

  $var =  sha1($var);

       $generator = array(
                'a'   =>  'b8', 'b'   =>  '4v',
	            'c'   =>  'un', 'h'   =>  'cg',
	            'e'   =>  'zy', 'f'   =>  '6q',
	            'g'   =>  '5r', 'j'   =>  'z6',
	            'k'   =>  's0', 'u'   =>  '8g',
	            't'   =>  'jk', 's'   =>  'ng',
                'v'   =>  'yp', 'x'   =>  'tj',
                'w'   =>  '24', 'z'   =>  'z9',
	            'y'   =>  'hc', 'q'   =>  'py',	  
	            'r'   =>  'e1', 'm'   =>  'y9',
                '0'   =>  'nh', '1'   =>  '9h',
                '2'   =>  'e2', '3'   =>  '4n',
                '4'   =>  '1x', '5'   =>  'sz',
                '6'   =>  'qe', '7'   =>  '9r',
                '8'   =>  'vs', '9'   =>  'q3',
              );

		$var = strtr($var, $generator);
        $var = substr( $var, 0, 20 );

	return md5( $var );
}