Php code converter to VB.NET

<?php
   /**
    * Function to fetch access token
    */
       function get_token($userName, $userPassword) {
            //init the url
            $Url = "http://api.abcdtesting.net/json/token";
            //encapsulate the credentials into a base64 string
            $authString = base64_encode($userName . ":" . $userPassword);

            //init header array
            $header = array();
            $header[] = 'Content-length: 0';
            $header[] = 'Content-type: application/json';
            $header[] = 'Authorization:' . $authString;

            //init curl api and send request - returning $data
            $ch = curl_init();
            $timeout = 5;
            curl_setopt($ch, CURLOPT_URL, $Url);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
            curl_setopt($ch, CURLOPT_HTTPHEADER, $header);
            curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $timeout);
            $data = curl_exec($ch);

            //process response - return token or assert error
            if (curl_errno($ch)) {
               echo 'error:' . curl_error($ch) . '<br/>';
               curl_close($ch);
            return '';
            } else {
              //token valid
              $tk = json_decode($data, true);
              curl_close($ch);
              return $tk[0]['token'];
            }
        }

I need to write the below php code in in vb.net .Can somebody help me?
Is there any code converter from php to vb.net? 

<pre><?php
   /**
    * Function to fetch access token
    */
       function get_token($userName, $userPassword) {
            //init the url
            $Url = "http://api.abcdtesting.net/json/token";
            //encapsulate the credentials into a base64 string
            $authString = base64_encode($userName . ":" . $userPassword);

            //init header array
            $header = array();
            $header[] = 'Content-length: 0';
            $header[] = 'Content-type: application/json';
            $header[] = 'Authorization:' . $authString;

            //init curl api and send request - returning $data
            $ch = curl_init();
            $timeout = 5;
            curl_setopt($ch, CURLOPT_URL, $Url);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
            curl_setopt($ch, CURLOPT_HTTPHEADER, $header);
            curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $timeout);
            $data = curl_exec($ch);

            //process response - return token or assert error
            if (curl_errno($ch)) {
               echo 'error:' . curl_error($ch) . '<br/>';
               curl_close($ch);
            return '';
            } else {
              //token valid
              $tk = json_decode($data, true);
              curl_close($ch);
              return $tk[0]['token'];
            }
        }