Map<String, Object> options = new HashMap<String, Object>();
		options.put("modal", true);
		options.put("draggable", true);
		options.put("resizable", false);
		options.put("contentWidth", 370);
		options.put("contentHeight", 150);
		options.put("includeViewParams", true);
		

		Map<String, List<String>> params = new HashMap<String, List<String>>();
		ArrayList<String> p = new ArrayList<String>();
		p.add("123");
		params.put("grpId", p);		 
		
		RequestContext context = RequestContext.getCurrentInstance();
		context.addCallbackParam("selectedGroupUser", selectedGroupUser);
		 
		context.openDialog("xhtml/group-user-view",
				options, params);

RequestContext context = RequestContext.getCurrentInstance();