object.ComputerName

<package>
   <job id="vbs">
      <script language="VBScript">
         Set WshNetwork = WScript.CreateObject("WScript.Network")
         WScript.Echo "Domain = " & WshNetwork.UserDomain
         WScript.Echo "Computer Name = " & WshNetwork.ComputerName
         WScript.Echo "User Name = " & WshNetwork.UserName
      </script>
   </job>
   <job id="js">
      <script language="JScript">
         var WshNetwork = WScript.CreateObject("WScript.Network");
         WScript.Echo("Domain = " + WshNetwork.UserDomain);
         WScript.Echo("Computer Name = " + WshNetwork.ComputerName);
         WScript.Echo("User Name = " + WshNetwork.UserName);
         }
      </script>
   </job>
</package>