function sendUnicode()

[tvelkovski]

Change:
curl_setopt($ch, CURLOPT_URL, $this->base_url_SendSMSUnicode);
to:
curl_setopt($ch, CURLOPT_URL, $this->base_url_SendSMS);

Change:
$fieldstring = "username=$this->username&password=$this->password&api_key=$this->api_key&FROM=$this->from&to=$this->to&text=$this->msgtext&type=unicode";
to:
$fieldstring = "username=$this->username&password=$this->password&api_key=$this->apikey&FROM=$this->from&to=$this->to&text=$this->msgtext&type=unicode";