title: Find user-control's control from another user-control in same page
body: <p>I have created an <code>usercontrol</code> that has <code>treeview</code> inside.<br/><br/>
  Now I have placed it in an <code>aspx page</code> twice with some different <code>Id</code> let us say <code>usercontrolA</code> and <code>usercontrolB</code>.<br/><br/>
  Both of them are loaded in to page one by one.<br/>
  Now in <code>pre-render event</code> of <code>usercontrolA</code> I want to get the object of <code>treeview</code> control of <code>usercontrolB</code>.<br/><br/> How can I achieve it?<br/></p>