Calling Java script from java using DWR not updating input field in browser

[Adnan Gondal]

I am calling java script from java using the DWR mechanism with below code

Container container = ServerContextFactory.get().getContainer();
ScriptSessionManager manager = (ScriptSessionManager) container.getBean(ScriptSessionManager.class);
Collection sessions = manager.getAllScriptSessions();
Util utilAll = new Util(sessions);
utilAll.setStyle("isTreeUpdatedButton", "background-color", "#33C");

It is executing successfully but the input field's background(element having id isTreeUpdatedButton) color is not updating, and an alert comes saying "invalid assignment left-hand side" when above code is executed.