how 2 create an Object in JavaScript

[lirlir]

to create a object in VBScript i write the next code:

<%
set rs = server.CreateObject("ADODB.Recordset");
set OBus =server.CreateObject
("TreeBusiness.clsTreeBusiness");
call OBus.InitializeLogin
("10.10.10.8","project_liron","sa","sa");
%>

how can i do the same in JavaScript ?