http_build_url for Javascript

function http_build_url (urlComponents)
{
  var key = ['source', 'scheme', 'authority', 'userInfo', 'user', 'pass', 'host', 'port', 'relative', 'path', 'directory', 'file', 'query', 'fragment'];
  var result = '';
  var val = '';
  for (var i = 0; i < key.length; i++)
  {
    val = key[i];
    val = urlComponents[val];
    if (val != undefined)
    {
      switch(i)
      {
        // Scheme
        case 1:
          result += val + '://';
          break;
        // Username
        case 4:
        // Port
        case 7:
          result += val + ':';
          break;
        // Password
        case 5:
          result += val + '@';
          break;
        // Host
        case 6:
        // Path
        case 9:
        // Directory
        case 10:
        // File
        case 11:
          result += val;
          break;
        // Query
        case 12:
          result += '?' + val;
          break;
        // Fragment
        case 13:
          result += '#' + val;
          break;
      }
    }
  }

  return result;
}