Who's online & Contact form error

Internet Creating Weather Web Sites
1

I’m using the latest version of Mike’s Who’s Online script and v3.1.2 of his Contact form.
When someone tried to send me a message using the contact form them get this error once the form has been completed and submitted:

Fatal error: Cannot redeclare geoip_country_code_by_name() in /home/users/uks11934/html/hebwx.co.uk/whos-online/include-whos-online-geoip.php on line 379

Line 379 in the script is the last line for this function:

function geoip_country_code_by_name($gi, $name) {
  $country_id = geoip_country_id_by_name($gi,$name);
  if ($country_id !== false) {
        return $gi->GEOIP_COUNTRY_CODES[$country_id];
  }
  return false;
}

Without removing the Who’s online script, has anyone got any ideas what may be causing this and how to sort it so I can get the contact form working again?