bool       PEAR_Config::set ( 
      string $key
       , string $value
       , string $layer = 'user'
     )
      Set a config value in a specific layer (defaults to 
      'user'). Enforces the types defined 
      in the configuration_info array.  An integer config 
      variable will be cast to int, and a set config 
      variable will be validated against its legal values.
$key
       config key
$value
       config value
$layer
       config layer
     bool -
     Returns TRUE on success, FALSE on failure.
    
This function can not be called statically.