$config = &CRM_Core_Config::singleton();
$this->icsfile = tempnam($config->customFileUploadDir, 'ics');
if ($this->icsfile !== FALSE) {
$config = &CRM_Core_Config::singleton();
$this->icsfile = tempnam($config->customFileUploadDir, 'ics');
if ($this->icsfile !== FALSE) {